SlideShare a Scribd company logo
1 of 32
Download to read offline
‫يم‬ِ‫ح‬‫ه‬‫الر‬ ِ‫ن‬َ‫م‬ْ‫ح‬‫ه‬‫الر‬ ِ ‫ه‬
‫اَّلل‬ ِ‫م‬ ْ
‫س‬ِ‫ب‬
In the name of Allah, the Beneficent, the Merciful
Welcome
To
The Presentation
Acknowledgment
We would like to thank Mahabubur Rahman Sir for giving me an
opportunity to express such a important topic via mathematical
presentation. I am also thankful to our friends for their ideas and co-
operation they provided to me. I am grateful to all of them.
Who I am...
S.M. Fazla Rabbi
Roll No. 37
Batch E-53
Department of CSE
Special Thanks to...
Chairman
Department of
Computer science and Engineering
For
Giving
Me
opportunity
Number Systems in
Mathematics
Presentation
on
Why need to learn?
▪ To represent numbers
▪ To know about different system
▪ How number system works
Content
Introduction
Classification
Discussion
History
Question
1
2
3
4
5
Introduction
A number system defines a set of values used to represent a quantity.
We talk about the number of people attending school, number of
modules taken per student etc.
Quantifying items and values in relation to each other is helpful for us
to make sense of our environment.
The study of numbers is not only related to computers. We apply
numbers everyday, and knowing how numbers work, will give us an
insight of how computers manipulate and store numbers.
Brief Introduction About Numbers
A number is a mathematical object used in counting
and measuring. It is used in counting and measuring.
Numerals are often used for labels, for ordering serial
numbers, and for codes like ISBNs. In mathematics,
the definition of number has been extended over the
years to include such numbers as zero, negative
numbers, rational numbers, irrational numbers, and
complex numbers.
The history of number system
Modern Number System came
from different civilizations
The history of number system
The Ancient Egyptians
The Ancient Egyptians experimented with duo-decimal
(base-12) system in which they counted finger-joints
instead of finger . Each of our finger has three joints. In
addition to their base-twelve system, the Egyptians also
experimented with a sort –of-base-ten system. In this
system , the number 1 through 9 were drawn using the
appropriate number of vertical lines.
A human hand palm was the way
of counting used by the
Egyptians…
The history of number system
The Ancient Babylonians
Babylonians, were famous for their astrological observations
and calculations, and used a sexagesimal (base-60)
numbering system. In addition to using base sixty, the
babylonians also made use of six and ten as sub-bases. The
babylonians sexagesimal system which first appeared around
1900 to 1800 BC, is also credited with being the first known
place-value of a particular digit depends on both the digit
itself and its position within the number . This as an
extremely important development, because – prior to place-
value system – people were obliged to use different symbol to
represent different power of a base.
The history of number system
Aztecs, Eskimos, And Indian Merchants
Other cultures such as the Aztecs, developed vigesimal (base-
20) systems because they counted using both finger and toes.
The Ainu of Japan and the Eskimos of Greenland are two of
the peoples who make use of vigesimal systems of present day
. Another system that is relatively easy to understand is
quinary (base-5), which uses five digit : 0, 1, 2, 3, and 4. The
system is particularly interesting , in that a quinary finger-
counting scheme is still in use today by Indian merchant
near Bombay . This allow them to perform calculations on one
hand while serving their customers with the other.
Aztecs were the ethnic
group of Mexico
The history of number system
Mayan number system
This system is unique to our current decimal system, as
our current decimal system uses base -10 whereas, the
Mayan Number System uses base- 20.
The Mayan system used a combination of two symbols.
A dot (.) was used to represent the units and a dash (-)
was used to represent five. The Mayan's wrote their
numbers vertically as opposed to horizontally with the
lowest denomination on the bottom.
Several numbers according to Mayan
Number System
Binary number system
The binary numeral system, or base-2 number system,
represents numeric values using two symbols, 0 and 1. More
specifically, the usual base-2 system is a positional notation
with a radix of 2. Owing to its straight forward implementation
in digital electronic circuitry using logic gates, the binary
system is used internally by all modern computers. Counting in
binary is similar to counting in any other number system.
Beginning with a single digit, counting proceeds through each
symbol, in increasing order. Decimal counting uses the symbols
0 through 9, while binary only uses the symbols 0 and 1.
The history of number system
The history of number system
Fractions and Ancient Egypt
Ancient Egyptians had an understanding of fractions, however they
did not write simple fractions as 3/5 or 4/9 because of restrictions
in notation. The Egyptian scribe wrote fractions with the
numerator of 1. They used the hieroglyph “an open mouth" above
the number to indicate its reciprocal. The number 5, written, as a
fraction 1/5 would be written as . . .There are some exceptions.
There was a special hieroglyph for 2/3, , and some evidence that
3/4 also had a special hieroglyph. All other fractions were written
as the sum of unit fractions. For example 3/8 was written as 1/4 +
1/8.
The history of number system
Finally, In the sections following this one, we will give a chronological survey of number
systems throughout our mathematical history. We begin with prehistoric number systems,
which—in a way—predate even counting. We then travel through the proverbial wormhole,
if you will, and arrive at about ~3000 B.C.E. where the Egyptians are ruling supreme. Not
alone though, as the Summerians are more or less side by side and show signs of a much
higher mathematical understanding (~3000 B.C.E.). As the Summerians more or less
become the Babylonians around 2000 B.C.E. The Chinese, working largely in isolation, are
next: ~2500 B.C.E. Greek mathematicians become a reckoned—in more than one sense of
the word—force around 500 B.C.E. The mathematically impaired Romans provide no real
mathematical interest, but rotationally they are of large interest (~0 C.E.). Four hundred
years later (~400 C.E.) and across the globe, the astrologists of the Mayan civilization are
making incredible computations using, what seems to be, a number system developed in
isolation. The Hindus make achievements during a long period of time. Perhaps the most
important ones to us around 300 B.C.E. to 400 C.E. Then again, we make a rather big jump in
history and arrive in modern times, where we discuss computers and number systems.
Classification of Number System
Number Systems
Complex
Real
Rational
Imaginary
Irrational
Positive
Integer
Negative Zero Whole/ Non-negative
Natural
Composite
Fraction
Odd
Even
Prime
Terminating and
Repeating
NoTerminating and No
Repeating
Discussion
On various types of number
Prime & Composite
A prime number (or a prime) is a natural number greater than 1 that has no positive divisors
other than 1 and itself.
There are hints in the surviving records of the ancient Egyptians that they had some knowledge of prime
numbers: the Egyptian fraction expansions in the Rhind papyrus, for instance, have quite different forms for
primes and for composites. However, the earliest surviving records of the explicit study of prime numbers come
from the Ancient Greeks. Euclid's Elements (circa 300 BC) contain important theorems about primes
Example: 5 can only be divided evenly by 1 or 5, so it is a prime number.
When a number can be divided up evenly it is a Composite Number. Ex- 4,6,8,9….
Composite
History
Definition
Definition
Integer
An integer is a number that can be written without a fractional component . For example, 21, 4,
0, and −2048 are integers, while 9.75, 5 1⁄2, and √2 are not. Integer is denoted as Z.
Z= {……,-3,-2,-1,0,1,2,3,…..}
Whole/ Non-
negative
Odd
Even
Positive {1,2,3,…….}
Negative {….,-3,-2,-1,}
Zero { 0 }
{0,1,2,3,…….}
{2,4,6,8……}
Any integer that can be divided exactly by 2 is an even number.The last digit is 0, 2, 4, 6 or 8
Example: −24, 0, 6 and 38 are all even numbers.
{1,3,5,7,……}
Any integer that can be divided exactly by 2 is an even number.The last digit is 0, 2, 4, 6 or 8 .
Example: −3, 1, 7 and 35 are all odd numbers.
Zero’s origin>>4000 yrs Mesopotamia-Sumerian ”space”>>> third
century B.C. in ancient Babylon zero symbol >> 350 A.D.Mayans
calender.>>>seventh century A.D. in India mathematician
Brahmagupta >>>Middle East 773 A.D Mohammed ibn-Musa al-
Khowarizmi It was al-Khowarizmi who first synthesized Indian
arithmetic and showed how the zero could function in algebraic
equations.
Fraction
This is a type of a rational number. Fractions are written as two numbers, the numerator and the
denominator ,with a dividing bar between them. In the fraction m/n ‘m’ represents equal parts, where
‘n’ equal parts of that size make up one whole.
If the absolute value of m is greater than n ,then the absolute value of the fraction is greater than
1.Fractions can be greater than , less than ,or equal to1 and can also be positive ,negative , or zero.
Real
In mathematics, a real number is a value that represents a quantity along a line. The adjective real in this
context was introduced in the 17th century by René Descartes, who distinguished between real
and imaginary roots of polynomials. Julius Wilhelm Richard Dedekind was a German mathematician who
made important contributions to abstract algebra (particularly ring theory), algebraic number theory and
the foundations of the real numbers. The Real Numbers had no name before Imaginary Numbers were
thought of. Mathematician got called "Real" because they were not Imaginary.
Rules
* Real Numbers are measurable.The sets of real number, are those numbers
That can be mapped on a number line.
* Real Numbers have a concrete value
* Real Numbers can be manipulated, all can rewritten as a decimal
In mathematics, a real number is a value that represents a
quantity along a continuous line. The real numbers include
all the rational numbers, such as the integer −5 and
the fraction 4/3, and all the irrational numbers such as
√2 (1.41421356… the square root of two, an
irrational algebraic number) and π (3.14159265…, a
transcendental number).
History
Definition
Rational & Irrational
In mathematics, a rational number is any number that can be expressed
as the quotient or fraction p/q of two integers, a numerator p and a non-
zero denominator q. Since q may be equal to 1, every integer is a rational
number. Rational numbers are usually denoted by a boldface Q, it was
thus denoted in 1895 by Giuseppe Peano. Example: ⅛, ⅔.
History
&
Definition
Characteristics
Definition
Characteristics
Terminating>>> ½ = 0.5
Repeating>>> 10/3 =3.333333
No terminating & No repeating >>> √2= 1.4142135624 ………
The numbers cannot be written as a ratio of two integers are
called Irrational Numbers. Example: π (Pi) is a famous irrational
number. π = 3.1415926535897932384626433832795... (and more)
Imaginary
An imaginary number is a complex number that can be written as a real
number multiplied by the imaginary unit i, which is defined by its property i2 =
−1. The square of an imaginary number bi is −b2. For example, 5i is an imaginary number,
and its square is −25. Zero is considered to be both real and imaginary.
Greek mathematician and engineer Heron of Alexandria is noted as the first to have
conceived these numbers,Rafael Bombelli first set down the rules for multiplication of
complex numbers in 1572. The concept had appeared in print earlier, for instance in work
by Gerolamo Cardano.
Imaginary numbers can be very useful for solving engineering problems. On example is
if you have a pendulum swinging, it starts to slow down and eventually stop. If you want
to work out the motion of the pendulum over a certain time (ie derive a formula) then
the best way to do it is to use complex numbers.
History
Definition
Uses
Complex
A complex number is a number that can be expressed in the form a + bi,
where a and b are real numbers, and i is the imaginary unit (which satisfies
the equation i2 = −1). In this expression, a is called the real part of the
complex number, and b is called the imaginary part. If z=a+bi, then we
write {Re} (z)=a and {Im} (z)=b .
For example, −3.5 + 2i is a complex number.
The Italian mathematician Gerolamo Cardano is the first person known to have introduced complex
numbers. He called them "fictitious" during his attempts to find solutions to cubic equations in the 16th
century.
Complex numbers are the building blocks of more intricate math, such as
algebra. They can be applied to many aspects of real life, especially in
electronics and electromagnetism.
History
Definition
Uses
Other Types
There are different kind of other numbers too. It includes
hyper-real numbers,
hyper-complex numbers,
p-adic numbers,
surreal numbers etc.
These numbers are rarely used in our day-to-day life.
Therefore, we need not know about them in detail.
In Short
Natural, N={1,2,3,4,5……..}
Integer, I={-3,-2,-1,0,1,2,3}
Real, R=[-∞, +∞]
Rational, Q= {
𝑝
𝑞
, 𝑝, 𝑞 ∈ 𝐼, 𝑞 ≠ 0} ex.
1
2
=0.5 (Terminating),
10
3
=3.333333 (repeating)
Irrational, Qi={√2, √3, √5, √7} ex. 2 = 1.4142135624 (no terminating & no repeating)
Complex, Z= x+iy, x,y ∈ 𝑅 where, x= real part and iy= Imaginary part…we can say
All real number are Subset of complex number.
Imaginary, i = Square root of negative number. Ex. −1, −2, −3….Where i exist.
1) Binary Number System
A Binary number system has only two digits that are 0 and 1. Every number (value) represents
with 0 and 1 in this number system. The base of binary number system is 2, because it has only
two digits.
2) Octal number system
Octal number system has only eight (8) digits from 0 to 7. Every number (value) represents with
0,1,2,3,4,5,6 and 7 in this number system. The base of octal number system is 8, because it has
only 8 digits.
3) Decimal number system
Decimal number system has only ten (10) digits from 0 to 9. Every number (value) represents with
0,1,2,3,4,5,6, 7,8 and 9 in this number system. The base of decimal number system is 10, because it
has only 10 digits.
4) Hexadecimal number system
A Hexadecimal number system has sixteen (16) alphanumeric values from 0 to 9 and A to F. Every
number (value) represents with 0,1,2,3,4,5,6, 7,8,9,A,B,C,D,E and F in this number system. The
base of hexadecimal number system is 16, because it has 16 alphanumeric values. Here A is 10, B
is 11, C is 12, D is 13, E is 14 and F is 15.
Most popular number
systems
Used
In
Computer
System
And
Mathematics
Also
S o m e
R e f e r e n c e s
Work behind
en.wikipedia.org
www.archimedes-lab.org
www.math.chalmers.se www.slideshare.net
www.google.com
translate.google.com
www.mathsisfun.com www.youtube.com
www.purple-math.com
www.whatis.techtarget.com www.basic-mathematics.com
Thank you !
Anything else?

More Related Content

What's hot

Number systems
Number systemsNumber systems
Number systemsAnkit Goel
 
Maths PPT on NUMBER SYSTEM
Maths PPT on NUMBER SYSTEMMaths PPT on NUMBER SYSTEM
Maths PPT on NUMBER SYSTEMKANIKA59
 
The mystery of zero presentation
The mystery of zero presentationThe mystery of zero presentation
The mystery of zero presentationZulfikar Dipto
 
Importance of zero
Importance of zeroImportance of zero
Importance of zeromalinibindra
 
Mathematical concepts and their applications: Number system
Mathematical concepts and their applications: Number systemMathematical concepts and their applications: Number system
Mathematical concepts and their applications: Number systemJesstern Rays
 
History of Zero - Mathematics
History of  Zero - MathematicsHistory of  Zero - Mathematics
History of Zero - Mathematicsdivya rajput
 
History of hindu arabic numerals
History of hindu arabic numeralsHistory of hindu arabic numerals
History of hindu arabic numeralsAlfiramita Hertanti
 
2.1 lbd numbers and their practical applications
2.1   lbd numbers and their practical applications2.1   lbd numbers and their practical applications
2.1 lbd numbers and their practical applicationsRaechel Lim
 
Evolution on number
Evolution on numberEvolution on number
Evolution on numberdhunda munda
 

What's hot (20)

Zero
ZeroZero
Zero
 
Number systems
Number systemsNumber systems
Number systems
 
Maths PPT on NUMBER SYSTEM
Maths PPT on NUMBER SYSTEMMaths PPT on NUMBER SYSTEM
Maths PPT on NUMBER SYSTEM
 
The mystery of zero presentation
The mystery of zero presentationThe mystery of zero presentation
The mystery of zero presentation
 
The story of Zero
The story of ZeroThe story of Zero
The story of Zero
 
Importance of zero
Importance of zeroImportance of zero
Importance of zero
 
Number system
Number systemNumber system
Number system
 
Zero
ZeroZero
Zero
 
Number System
Number SystemNumber System
Number System
 
Zzzzz
ZzzzzZzzzz
Zzzzz
 
Mathematical concepts and their applications: Number system
Mathematical concepts and their applications: Number systemMathematical concepts and their applications: Number system
Mathematical concepts and their applications: Number system
 
Maths number system
Maths   number systemMaths   number system
Maths number system
 
History of Zero - Mathematics
History of  Zero - MathematicsHistory of  Zero - Mathematics
History of Zero - Mathematics
 
Zero
ZeroZero
Zero
 
Zero: Origin
Zero: OriginZero: Origin
Zero: Origin
 
Journey of zero by lalit kharb
Journey of zero by lalit kharbJourney of zero by lalit kharb
Journey of zero by lalit kharb
 
History of hindu arabic numerals
History of hindu arabic numeralsHistory of hindu arabic numerals
History of hindu arabic numerals
 
2.1 lbd numbers and their practical applications
2.1   lbd numbers and their practical applications2.1   lbd numbers and their practical applications
2.1 lbd numbers and their practical applications
 
maths
mathsmaths
maths
 
Evolution on number
Evolution on numberEvolution on number
Evolution on number
 

Similar to Number system in Mathematics

fullhist6-23-05.pdf
fullhist6-23-05.pdffullhist6-23-05.pdf
fullhist6-23-05.pdfreginegraza
 
EDMA163 Exploring Mathematics And Numeracy.docx
EDMA163 Exploring Mathematics And Numeracy.docxEDMA163 Exploring Mathematics And Numeracy.docx
EDMA163 Exploring Mathematics And Numeracy.docx4934bk
 
The Mesopotamian culture is often called Babylonian, after the lar.docx
The Mesopotamian culture is often called Babylonian, after the lar.docxThe Mesopotamian culture is often called Babylonian, after the lar.docx
The Mesopotamian culture is often called Babylonian, after the lar.docxoreo10
 
History Of Mathematics
History Of MathematicsHistory Of Mathematics
History Of MathematicsBennet Hailink
 
Music of the spheres learning.pdf
Music of the spheres learning.pdfMusic of the spheres learning.pdf
Music of the spheres learning.pdftrungvo92
 
Maths in daily life
Maths in daily lifeMaths in daily life
Maths in daily lifeLavanya
 
Origin, history and application of Zero.
Origin, history and application of Zero.Origin, history and application of Zero.
Origin, history and application of Zero.Vishwanath Foundation
 
JOURNEY OF MATHS OVER A PERIOD OF TIME..................................
JOURNEY OF MATHS OVER A PERIOD OF TIME..................................JOURNEY OF MATHS OVER A PERIOD OF TIME..................................
JOURNEY OF MATHS OVER A PERIOD OF TIME..................................Pratik Sidhu
 

Similar to Number system in Mathematics (19)

fullhist6-23-05.pdf
fullhist6-23-05.pdffullhist6-23-05.pdf
fullhist6-23-05.pdf
 
EDMA163 Exploring Mathematics And Numeracy.docx
EDMA163 Exploring Mathematics And Numeracy.docxEDMA163 Exploring Mathematics And Numeracy.docx
EDMA163 Exploring Mathematics And Numeracy.docx
 
The Mesopotamian culture is often called Babylonian, after the lar.docx
The Mesopotamian culture is often called Babylonian, after the lar.docxThe Mesopotamian culture is often called Babylonian, after the lar.docx
The Mesopotamian culture is often called Babylonian, after the lar.docx
 
History Of Mathematics
History Of MathematicsHistory Of Mathematics
History Of Mathematics
 
STLD Unit 1
STLD Unit 1STLD Unit 1
STLD Unit 1
 
numerals.pptx
numerals.pptxnumerals.pptx
numerals.pptx
 
NUMERATION SYSTEM
NUMERATION SYSTEMNUMERATION SYSTEM
NUMERATION SYSTEM
 
History
HistoryHistory
History
 
History And History Of Math
History And History Of MathHistory And History Of Math
History And History Of Math
 
Math term paper
Math term paperMath term paper
Math term paper
 
Music of the spheres learning.pdf
Music of the spheres learning.pdfMusic of the spheres learning.pdf
Music of the spheres learning.pdf
 
Maths in daily life
Maths in daily lifeMaths in daily life
Maths in daily life
 
Origin, history and application of Zero.
Origin, history and application of Zero.Origin, history and application of Zero.
Origin, history and application of Zero.
 
JOURNEY OF MATHS OVER A PERIOD OF TIME..................................
JOURNEY OF MATHS OVER A PERIOD OF TIME..................................JOURNEY OF MATHS OVER A PERIOD OF TIME..................................
JOURNEY OF MATHS OVER A PERIOD OF TIME..................................
 
The birth of algebra
The birth of algebraThe birth of algebra
The birth of algebra
 
History of Math
History of MathHistory of Math
History of Math
 
şErife özder
şErife özderşErife özder
şErife özder
 
şErife özder
şErife özderşErife özder
şErife özder
 
şerife özder
şerife özderşerife özder
şerife özder
 

More from S.M. Fazla Rabbi

CV and Resume Writing for Job
CV and Resume Writing for JobCV and Resume Writing for Job
CV and Resume Writing for JobS.M. Fazla Rabbi
 
Student portal system application -Project Book
Student portal system application -Project BookStudent portal system application -Project Book
Student portal system application -Project BookS.M. Fazla Rabbi
 
Final Project presentation (on App devlopment)
Final Project presentation (on App devlopment)Final Project presentation (on App devlopment)
Final Project presentation (on App devlopment)S.M. Fazla Rabbi
 
Smart Notice Board with android app via Bluetooth
Smart Notice Board with android app via BluetoothSmart Notice Board with android app via Bluetooth
Smart Notice Board with android app via BluetoothS.M. Fazla Rabbi
 
The Game of Cricket: Its History & Present
The Game of Cricket: Its History & Present The Game of Cricket: Its History & Present
The Game of Cricket: Its History & Present S.M. Fazla Rabbi
 

More from S.M. Fazla Rabbi (7)

CV and Resume Writing for Job
CV and Resume Writing for JobCV and Resume Writing for Job
CV and Resume Writing for Job
 
Student portal system application -Project Book
Student portal system application -Project BookStudent portal system application -Project Book
Student portal system application -Project Book
 
Final Project presentation (on App devlopment)
Final Project presentation (on App devlopment)Final Project presentation (on App devlopment)
Final Project presentation (on App devlopment)
 
Smart Notice Board with android app via Bluetooth
Smart Notice Board with android app via BluetoothSmart Notice Board with android app via Bluetooth
Smart Notice Board with android app via Bluetooth
 
The Game of Cricket: Its History & Present
The Game of Cricket: Its History & Present The Game of Cricket: Its History & Present
The Game of Cricket: Its History & Present
 
The Story Of Titanic
The Story Of Titanic The Story Of Titanic
The Story Of Titanic
 
Valentines day's Info
 Valentines day's Info Valentines day's Info
Valentines day's Info
 

Recently uploaded

Sulphonamides, mechanisms and their uses
Sulphonamides, mechanisms and their usesSulphonamides, mechanisms and their uses
Sulphonamides, mechanisms and their usesVijayaLaxmi84
 
4.9.24 Social Capital and Social Exclusion.pptx
4.9.24 Social Capital and Social Exclusion.pptx4.9.24 Social Capital and Social Exclusion.pptx
4.9.24 Social Capital and Social Exclusion.pptxmary850239
 
CLASSIFICATION OF ANTI - CANCER DRUGS.pptx
CLASSIFICATION OF ANTI - CANCER DRUGS.pptxCLASSIFICATION OF ANTI - CANCER DRUGS.pptx
CLASSIFICATION OF ANTI - CANCER DRUGS.pptxAnupam32727
 
Grade Three -ELLNA-REVIEWER-ENGLISH.pptx
Grade Three -ELLNA-REVIEWER-ENGLISH.pptxGrade Three -ELLNA-REVIEWER-ENGLISH.pptx
Grade Three -ELLNA-REVIEWER-ENGLISH.pptxkarenfajardo43
 
ICS 2208 Lecture Slide Notes for Topic 6
ICS 2208 Lecture Slide Notes for Topic 6ICS 2208 Lecture Slide Notes for Topic 6
ICS 2208 Lecture Slide Notes for Topic 6Vanessa Camilleri
 
Decoding the Tweet _ Practical Criticism in the Age of Hashtag.pptx
Decoding the Tweet _ Practical Criticism in the Age of Hashtag.pptxDecoding the Tweet _ Practical Criticism in the Age of Hashtag.pptx
Decoding the Tweet _ Practical Criticism in the Age of Hashtag.pptxDhatriParmar
 
Employablity presentation and Future Career Plan.pptx
Employablity presentation and Future Career Plan.pptxEmployablity presentation and Future Career Plan.pptx
Employablity presentation and Future Career Plan.pptxryandux83rd
 
Unraveling Hypertext_ Analyzing Postmodern Elements in Literature.pptx
Unraveling Hypertext_ Analyzing  Postmodern Elements in  Literature.pptxUnraveling Hypertext_ Analyzing  Postmodern Elements in  Literature.pptx
Unraveling Hypertext_ Analyzing Postmodern Elements in Literature.pptxDhatriParmar
 
How to Uninstall a Module in Odoo 17 Using Command Line
How to Uninstall a Module in Odoo 17 Using Command LineHow to Uninstall a Module in Odoo 17 Using Command Line
How to Uninstall a Module in Odoo 17 Using Command LineCeline George
 
MS4 level being good citizen -imperative- (1) (1).pdf
MS4 level   being good citizen -imperative- (1) (1).pdfMS4 level   being good citizen -imperative- (1) (1).pdf
MS4 level being good citizen -imperative- (1) (1).pdfMr Bounab Samir
 
PART 1 - CHAPTER 1 - CELL THE FUNDAMENTAL UNIT OF LIFE
PART 1 - CHAPTER 1 - CELL THE FUNDAMENTAL UNIT OF LIFEPART 1 - CHAPTER 1 - CELL THE FUNDAMENTAL UNIT OF LIFE
PART 1 - CHAPTER 1 - CELL THE FUNDAMENTAL UNIT OF LIFEMISSRITIMABIOLOGYEXP
 
31 ĐỀ THI THỬ VÀO LỚP 10 - TIẾNG ANH - FORM MỚI 2025 - 40 CÂU HỎI - BÙI VĂN V...
31 ĐỀ THI THỬ VÀO LỚP 10 - TIẾNG ANH - FORM MỚI 2025 - 40 CÂU HỎI - BÙI VĂN V...31 ĐỀ THI THỬ VÀO LỚP 10 - TIẾNG ANH - FORM MỚI 2025 - 40 CÂU HỎI - BÙI VĂN V...
31 ĐỀ THI THỬ VÀO LỚP 10 - TIẾNG ANH - FORM MỚI 2025 - 40 CÂU HỎI - BÙI VĂN V...Nguyen Thanh Tu Collection
 
BIOCHEMISTRY-CARBOHYDRATE METABOLISM CHAPTER 2.pptx
BIOCHEMISTRY-CARBOHYDRATE METABOLISM CHAPTER 2.pptxBIOCHEMISTRY-CARBOHYDRATE METABOLISM CHAPTER 2.pptx
BIOCHEMISTRY-CARBOHYDRATE METABOLISM CHAPTER 2.pptxSayali Powar
 
BÀI TẬP BỔ TRỢ 4 KĨ NĂNG TIẾNG ANH LỚP 8 - CẢ NĂM - GLOBAL SUCCESS - NĂM HỌC ...
BÀI TẬP BỔ TRỢ 4 KĨ NĂNG TIẾNG ANH LỚP 8 - CẢ NĂM - GLOBAL SUCCESS - NĂM HỌC ...BÀI TẬP BỔ TRỢ 4 KĨ NĂNG TIẾNG ANH LỚP 8 - CẢ NĂM - GLOBAL SUCCESS - NĂM HỌC ...
BÀI TẬP BỔ TRỢ 4 KĨ NĂNG TIẾNG ANH LỚP 8 - CẢ NĂM - GLOBAL SUCCESS - NĂM HỌC ...Nguyen Thanh Tu Collection
 
Healthy Minds, Flourishing Lives: A Philosophical Approach to Mental Health a...
Healthy Minds, Flourishing Lives: A Philosophical Approach to Mental Health a...Healthy Minds, Flourishing Lives: A Philosophical Approach to Mental Health a...
Healthy Minds, Flourishing Lives: A Philosophical Approach to Mental Health a...Osopher
 
An Overview of the Calendar App in Odoo 17 ERP
An Overview of the Calendar App in Odoo 17 ERPAn Overview of the Calendar App in Odoo 17 ERP
An Overview of the Calendar App in Odoo 17 ERPCeline George
 
BÀI TẬP BỔ TRỢ TIẾNG ANH 8 - I-LEARN SMART WORLD - CẢ NĂM - CÓ FILE NGHE (BẢN...
BÀI TẬP BỔ TRỢ TIẾNG ANH 8 - I-LEARN SMART WORLD - CẢ NĂM - CÓ FILE NGHE (BẢN...BÀI TẬP BỔ TRỢ TIẾNG ANH 8 - I-LEARN SMART WORLD - CẢ NĂM - CÓ FILE NGHE (BẢN...
BÀI TẬP BỔ TRỢ TIẾNG ANH 8 - I-LEARN SMART WORLD - CẢ NĂM - CÓ FILE NGHE (BẢN...Nguyen Thanh Tu Collection
 
Objectives n learning outcoms - MD 20240404.pptx
Objectives n learning outcoms - MD 20240404.pptxObjectives n learning outcoms - MD 20240404.pptx
Objectives n learning outcoms - MD 20240404.pptxMadhavi Dharankar
 
4.9.24 School Desegregation in Boston.pptx
4.9.24 School Desegregation in Boston.pptx4.9.24 School Desegregation in Boston.pptx
4.9.24 School Desegregation in Boston.pptxmary850239
 

Recently uploaded (20)

Sulphonamides, mechanisms and their uses
Sulphonamides, mechanisms and their usesSulphonamides, mechanisms and their uses
Sulphonamides, mechanisms and their uses
 
4.9.24 Social Capital and Social Exclusion.pptx
4.9.24 Social Capital and Social Exclusion.pptx4.9.24 Social Capital and Social Exclusion.pptx
4.9.24 Social Capital and Social Exclusion.pptx
 
CLASSIFICATION OF ANTI - CANCER DRUGS.pptx
CLASSIFICATION OF ANTI - CANCER DRUGS.pptxCLASSIFICATION OF ANTI - CANCER DRUGS.pptx
CLASSIFICATION OF ANTI - CANCER DRUGS.pptx
 
Grade Three -ELLNA-REVIEWER-ENGLISH.pptx
Grade Three -ELLNA-REVIEWER-ENGLISH.pptxGrade Three -ELLNA-REVIEWER-ENGLISH.pptx
Grade Three -ELLNA-REVIEWER-ENGLISH.pptx
 
ICS 2208 Lecture Slide Notes for Topic 6
ICS 2208 Lecture Slide Notes for Topic 6ICS 2208 Lecture Slide Notes for Topic 6
ICS 2208 Lecture Slide Notes for Topic 6
 
Decoding the Tweet _ Practical Criticism in the Age of Hashtag.pptx
Decoding the Tweet _ Practical Criticism in the Age of Hashtag.pptxDecoding the Tweet _ Practical Criticism in the Age of Hashtag.pptx
Decoding the Tweet _ Practical Criticism in the Age of Hashtag.pptx
 
Employablity presentation and Future Career Plan.pptx
Employablity presentation and Future Career Plan.pptxEmployablity presentation and Future Career Plan.pptx
Employablity presentation and Future Career Plan.pptx
 
Unraveling Hypertext_ Analyzing Postmodern Elements in Literature.pptx
Unraveling Hypertext_ Analyzing  Postmodern Elements in  Literature.pptxUnraveling Hypertext_ Analyzing  Postmodern Elements in  Literature.pptx
Unraveling Hypertext_ Analyzing Postmodern Elements in Literature.pptx
 
How to Uninstall a Module in Odoo 17 Using Command Line
How to Uninstall a Module in Odoo 17 Using Command LineHow to Uninstall a Module in Odoo 17 Using Command Line
How to Uninstall a Module in Odoo 17 Using Command Line
 
MS4 level being good citizen -imperative- (1) (1).pdf
MS4 level   being good citizen -imperative- (1) (1).pdfMS4 level   being good citizen -imperative- (1) (1).pdf
MS4 level being good citizen -imperative- (1) (1).pdf
 
CARNAVAL COM MAGIA E EUFORIA _
CARNAVAL COM MAGIA E EUFORIA            _CARNAVAL COM MAGIA E EUFORIA            _
CARNAVAL COM MAGIA E EUFORIA _
 
PART 1 - CHAPTER 1 - CELL THE FUNDAMENTAL UNIT OF LIFE
PART 1 - CHAPTER 1 - CELL THE FUNDAMENTAL UNIT OF LIFEPART 1 - CHAPTER 1 - CELL THE FUNDAMENTAL UNIT OF LIFE
PART 1 - CHAPTER 1 - CELL THE FUNDAMENTAL UNIT OF LIFE
 
31 ĐỀ THI THỬ VÀO LỚP 10 - TIẾNG ANH - FORM MỚI 2025 - 40 CÂU HỎI - BÙI VĂN V...
31 ĐỀ THI THỬ VÀO LỚP 10 - TIẾNG ANH - FORM MỚI 2025 - 40 CÂU HỎI - BÙI VĂN V...31 ĐỀ THI THỬ VÀO LỚP 10 - TIẾNG ANH - FORM MỚI 2025 - 40 CÂU HỎI - BÙI VĂN V...
31 ĐỀ THI THỬ VÀO LỚP 10 - TIẾNG ANH - FORM MỚI 2025 - 40 CÂU HỎI - BÙI VĂN V...
 
BIOCHEMISTRY-CARBOHYDRATE METABOLISM CHAPTER 2.pptx
BIOCHEMISTRY-CARBOHYDRATE METABOLISM CHAPTER 2.pptxBIOCHEMISTRY-CARBOHYDRATE METABOLISM CHAPTER 2.pptx
BIOCHEMISTRY-CARBOHYDRATE METABOLISM CHAPTER 2.pptx
 
BÀI TẬP BỔ TRỢ 4 KĨ NĂNG TIẾNG ANH LỚP 8 - CẢ NĂM - GLOBAL SUCCESS - NĂM HỌC ...
BÀI TẬP BỔ TRỢ 4 KĨ NĂNG TIẾNG ANH LỚP 8 - CẢ NĂM - GLOBAL SUCCESS - NĂM HỌC ...BÀI TẬP BỔ TRỢ 4 KĨ NĂNG TIẾNG ANH LỚP 8 - CẢ NĂM - GLOBAL SUCCESS - NĂM HỌC ...
BÀI TẬP BỔ TRỢ 4 KĨ NĂNG TIẾNG ANH LỚP 8 - CẢ NĂM - GLOBAL SUCCESS - NĂM HỌC ...
 
Healthy Minds, Flourishing Lives: A Philosophical Approach to Mental Health a...
Healthy Minds, Flourishing Lives: A Philosophical Approach to Mental Health a...Healthy Minds, Flourishing Lives: A Philosophical Approach to Mental Health a...
Healthy Minds, Flourishing Lives: A Philosophical Approach to Mental Health a...
 
An Overview of the Calendar App in Odoo 17 ERP
An Overview of the Calendar App in Odoo 17 ERPAn Overview of the Calendar App in Odoo 17 ERP
An Overview of the Calendar App in Odoo 17 ERP
 
BÀI TẬP BỔ TRỢ TIẾNG ANH 8 - I-LEARN SMART WORLD - CẢ NĂM - CÓ FILE NGHE (BẢN...
BÀI TẬP BỔ TRỢ TIẾNG ANH 8 - I-LEARN SMART WORLD - CẢ NĂM - CÓ FILE NGHE (BẢN...BÀI TẬP BỔ TRỢ TIẾNG ANH 8 - I-LEARN SMART WORLD - CẢ NĂM - CÓ FILE NGHE (BẢN...
BÀI TẬP BỔ TRỢ TIẾNG ANH 8 - I-LEARN SMART WORLD - CẢ NĂM - CÓ FILE NGHE (BẢN...
 
Objectives n learning outcoms - MD 20240404.pptx
Objectives n learning outcoms - MD 20240404.pptxObjectives n learning outcoms - MD 20240404.pptx
Objectives n learning outcoms - MD 20240404.pptx
 
4.9.24 School Desegregation in Boston.pptx
4.9.24 School Desegregation in Boston.pptx4.9.24 School Desegregation in Boston.pptx
4.9.24 School Desegregation in Boston.pptx
 

Number system in Mathematics

  • 1. ‫يم‬ِ‫ح‬‫ه‬‫الر‬ ِ‫ن‬َ‫م‬ْ‫ح‬‫ه‬‫الر‬ ِ ‫ه‬ ‫اَّلل‬ ِ‫م‬ ْ ‫س‬ِ‫ب‬ In the name of Allah, the Beneficent, the Merciful
  • 3. Acknowledgment We would like to thank Mahabubur Rahman Sir for giving me an opportunity to express such a important topic via mathematical presentation. I am also thankful to our friends for their ideas and co- operation they provided to me. I am grateful to all of them.
  • 4. Who I am... S.M. Fazla Rabbi Roll No. 37 Batch E-53 Department of CSE
  • 5. Special Thanks to... Chairman Department of Computer science and Engineering For Giving Me opportunity
  • 7. Why need to learn? ▪ To represent numbers ▪ To know about different system ▪ How number system works
  • 9. Introduction A number system defines a set of values used to represent a quantity. We talk about the number of people attending school, number of modules taken per student etc. Quantifying items and values in relation to each other is helpful for us to make sense of our environment. The study of numbers is not only related to computers. We apply numbers everyday, and knowing how numbers work, will give us an insight of how computers manipulate and store numbers.
  • 10. Brief Introduction About Numbers A number is a mathematical object used in counting and measuring. It is used in counting and measuring. Numerals are often used for labels, for ordering serial numbers, and for codes like ISBNs. In mathematics, the definition of number has been extended over the years to include such numbers as zero, negative numbers, rational numbers, irrational numbers, and complex numbers.
  • 11. The history of number system Modern Number System came from different civilizations
  • 12. The history of number system The Ancient Egyptians The Ancient Egyptians experimented with duo-decimal (base-12) system in which they counted finger-joints instead of finger . Each of our finger has three joints. In addition to their base-twelve system, the Egyptians also experimented with a sort –of-base-ten system. In this system , the number 1 through 9 were drawn using the appropriate number of vertical lines. A human hand palm was the way of counting used by the Egyptians…
  • 13. The history of number system The Ancient Babylonians Babylonians, were famous for their astrological observations and calculations, and used a sexagesimal (base-60) numbering system. In addition to using base sixty, the babylonians also made use of six and ten as sub-bases. The babylonians sexagesimal system which first appeared around 1900 to 1800 BC, is also credited with being the first known place-value of a particular digit depends on both the digit itself and its position within the number . This as an extremely important development, because – prior to place- value system – people were obliged to use different symbol to represent different power of a base.
  • 14. The history of number system Aztecs, Eskimos, And Indian Merchants Other cultures such as the Aztecs, developed vigesimal (base- 20) systems because they counted using both finger and toes. The Ainu of Japan and the Eskimos of Greenland are two of the peoples who make use of vigesimal systems of present day . Another system that is relatively easy to understand is quinary (base-5), which uses five digit : 0, 1, 2, 3, and 4. The system is particularly interesting , in that a quinary finger- counting scheme is still in use today by Indian merchant near Bombay . This allow them to perform calculations on one hand while serving their customers with the other. Aztecs were the ethnic group of Mexico
  • 15. The history of number system Mayan number system This system is unique to our current decimal system, as our current decimal system uses base -10 whereas, the Mayan Number System uses base- 20. The Mayan system used a combination of two symbols. A dot (.) was used to represent the units and a dash (-) was used to represent five. The Mayan's wrote their numbers vertically as opposed to horizontally with the lowest denomination on the bottom. Several numbers according to Mayan Number System
  • 16. Binary number system The binary numeral system, or base-2 number system, represents numeric values using two symbols, 0 and 1. More specifically, the usual base-2 system is a positional notation with a radix of 2. Owing to its straight forward implementation in digital electronic circuitry using logic gates, the binary system is used internally by all modern computers. Counting in binary is similar to counting in any other number system. Beginning with a single digit, counting proceeds through each symbol, in increasing order. Decimal counting uses the symbols 0 through 9, while binary only uses the symbols 0 and 1. The history of number system
  • 17. The history of number system Fractions and Ancient Egypt Ancient Egyptians had an understanding of fractions, however they did not write simple fractions as 3/5 or 4/9 because of restrictions in notation. The Egyptian scribe wrote fractions with the numerator of 1. They used the hieroglyph “an open mouth" above the number to indicate its reciprocal. The number 5, written, as a fraction 1/5 would be written as . . .There are some exceptions. There was a special hieroglyph for 2/3, , and some evidence that 3/4 also had a special hieroglyph. All other fractions were written as the sum of unit fractions. For example 3/8 was written as 1/4 + 1/8.
  • 18. The history of number system Finally, In the sections following this one, we will give a chronological survey of number systems throughout our mathematical history. We begin with prehistoric number systems, which—in a way—predate even counting. We then travel through the proverbial wormhole, if you will, and arrive at about ~3000 B.C.E. where the Egyptians are ruling supreme. Not alone though, as the Summerians are more or less side by side and show signs of a much higher mathematical understanding (~3000 B.C.E.). As the Summerians more or less become the Babylonians around 2000 B.C.E. The Chinese, working largely in isolation, are next: ~2500 B.C.E. Greek mathematicians become a reckoned—in more than one sense of the word—force around 500 B.C.E. The mathematically impaired Romans provide no real mathematical interest, but rotationally they are of large interest (~0 C.E.). Four hundred years later (~400 C.E.) and across the globe, the astrologists of the Mayan civilization are making incredible computations using, what seems to be, a number system developed in isolation. The Hindus make achievements during a long period of time. Perhaps the most important ones to us around 300 B.C.E. to 400 C.E. Then again, we make a rather big jump in history and arrive in modern times, where we discuss computers and number systems.
  • 19. Classification of Number System Number Systems Complex Real Rational Imaginary Irrational Positive Integer Negative Zero Whole/ Non-negative Natural Composite Fraction Odd Even Prime Terminating and Repeating NoTerminating and No Repeating
  • 21. Prime & Composite A prime number (or a prime) is a natural number greater than 1 that has no positive divisors other than 1 and itself. There are hints in the surviving records of the ancient Egyptians that they had some knowledge of prime numbers: the Egyptian fraction expansions in the Rhind papyrus, for instance, have quite different forms for primes and for composites. However, the earliest surviving records of the explicit study of prime numbers come from the Ancient Greeks. Euclid's Elements (circa 300 BC) contain important theorems about primes Example: 5 can only be divided evenly by 1 or 5, so it is a prime number. When a number can be divided up evenly it is a Composite Number. Ex- 4,6,8,9…. Composite History Definition Definition
  • 22. Integer An integer is a number that can be written without a fractional component . For example, 21, 4, 0, and −2048 are integers, while 9.75, 5 1⁄2, and √2 are not. Integer is denoted as Z. Z= {……,-3,-2,-1,0,1,2,3,…..} Whole/ Non- negative Odd Even Positive {1,2,3,…….} Negative {….,-3,-2,-1,} Zero { 0 } {0,1,2,3,…….} {2,4,6,8……} Any integer that can be divided exactly by 2 is an even number.The last digit is 0, 2, 4, 6 or 8 Example: −24, 0, 6 and 38 are all even numbers. {1,3,5,7,……} Any integer that can be divided exactly by 2 is an even number.The last digit is 0, 2, 4, 6 or 8 . Example: −3, 1, 7 and 35 are all odd numbers. Zero’s origin>>4000 yrs Mesopotamia-Sumerian ”space”>>> third century B.C. in ancient Babylon zero symbol >> 350 A.D.Mayans calender.>>>seventh century A.D. in India mathematician Brahmagupta >>>Middle East 773 A.D Mohammed ibn-Musa al- Khowarizmi It was al-Khowarizmi who first synthesized Indian arithmetic and showed how the zero could function in algebraic equations.
  • 23. Fraction This is a type of a rational number. Fractions are written as two numbers, the numerator and the denominator ,with a dividing bar between them. In the fraction m/n ‘m’ represents equal parts, where ‘n’ equal parts of that size make up one whole. If the absolute value of m is greater than n ,then the absolute value of the fraction is greater than 1.Fractions can be greater than , less than ,or equal to1 and can also be positive ,negative , or zero.
  • 24. Real In mathematics, a real number is a value that represents a quantity along a line. The adjective real in this context was introduced in the 17th century by René Descartes, who distinguished between real and imaginary roots of polynomials. Julius Wilhelm Richard Dedekind was a German mathematician who made important contributions to abstract algebra (particularly ring theory), algebraic number theory and the foundations of the real numbers. The Real Numbers had no name before Imaginary Numbers were thought of. Mathematician got called "Real" because they were not Imaginary. Rules * Real Numbers are measurable.The sets of real number, are those numbers That can be mapped on a number line. * Real Numbers have a concrete value * Real Numbers can be manipulated, all can rewritten as a decimal In mathematics, a real number is a value that represents a quantity along a continuous line. The real numbers include all the rational numbers, such as the integer −5 and the fraction 4/3, and all the irrational numbers such as √2 (1.41421356… the square root of two, an irrational algebraic number) and π (3.14159265…, a transcendental number). History Definition
  • 25. Rational & Irrational In mathematics, a rational number is any number that can be expressed as the quotient or fraction p/q of two integers, a numerator p and a non- zero denominator q. Since q may be equal to 1, every integer is a rational number. Rational numbers are usually denoted by a boldface Q, it was thus denoted in 1895 by Giuseppe Peano. Example: ⅛, ⅔. History & Definition Characteristics Definition Characteristics Terminating>>> ½ = 0.5 Repeating>>> 10/3 =3.333333 No terminating & No repeating >>> √2= 1.4142135624 ……… The numbers cannot be written as a ratio of two integers are called Irrational Numbers. Example: π (Pi) is a famous irrational number. π = 3.1415926535897932384626433832795... (and more)
  • 26. Imaginary An imaginary number is a complex number that can be written as a real number multiplied by the imaginary unit i, which is defined by its property i2 = −1. The square of an imaginary number bi is −b2. For example, 5i is an imaginary number, and its square is −25. Zero is considered to be both real and imaginary. Greek mathematician and engineer Heron of Alexandria is noted as the first to have conceived these numbers,Rafael Bombelli first set down the rules for multiplication of complex numbers in 1572. The concept had appeared in print earlier, for instance in work by Gerolamo Cardano. Imaginary numbers can be very useful for solving engineering problems. On example is if you have a pendulum swinging, it starts to slow down and eventually stop. If you want to work out the motion of the pendulum over a certain time (ie derive a formula) then the best way to do it is to use complex numbers. History Definition Uses
  • 27. Complex A complex number is a number that can be expressed in the form a + bi, where a and b are real numbers, and i is the imaginary unit (which satisfies the equation i2 = −1). In this expression, a is called the real part of the complex number, and b is called the imaginary part. If z=a+bi, then we write {Re} (z)=a and {Im} (z)=b . For example, −3.5 + 2i is a complex number. The Italian mathematician Gerolamo Cardano is the first person known to have introduced complex numbers. He called them "fictitious" during his attempts to find solutions to cubic equations in the 16th century. Complex numbers are the building blocks of more intricate math, such as algebra. They can be applied to many aspects of real life, especially in electronics and electromagnetism. History Definition Uses
  • 28. Other Types There are different kind of other numbers too. It includes hyper-real numbers, hyper-complex numbers, p-adic numbers, surreal numbers etc. These numbers are rarely used in our day-to-day life. Therefore, we need not know about them in detail.
  • 29. In Short Natural, N={1,2,3,4,5……..} Integer, I={-3,-2,-1,0,1,2,3} Real, R=[-∞, +∞] Rational, Q= { 𝑝 𝑞 , 𝑝, 𝑞 ∈ 𝐼, 𝑞 ≠ 0} ex. 1 2 =0.5 (Terminating), 10 3 =3.333333 (repeating) Irrational, Qi={√2, √3, √5, √7} ex. 2 = 1.4142135624 (no terminating & no repeating) Complex, Z= x+iy, x,y ∈ 𝑅 where, x= real part and iy= Imaginary part…we can say All real number are Subset of complex number. Imaginary, i = Square root of negative number. Ex. −1, −2, −3….Where i exist.
  • 30. 1) Binary Number System A Binary number system has only two digits that are 0 and 1. Every number (value) represents with 0 and 1 in this number system. The base of binary number system is 2, because it has only two digits. 2) Octal number system Octal number system has only eight (8) digits from 0 to 7. Every number (value) represents with 0,1,2,3,4,5,6 and 7 in this number system. The base of octal number system is 8, because it has only 8 digits. 3) Decimal number system Decimal number system has only ten (10) digits from 0 to 9. Every number (value) represents with 0,1,2,3,4,5,6, 7,8 and 9 in this number system. The base of decimal number system is 10, because it has only 10 digits. 4) Hexadecimal number system A Hexadecimal number system has sixteen (16) alphanumeric values from 0 to 9 and A to F. Every number (value) represents with 0,1,2,3,4,5,6, 7,8,9,A,B,C,D,E and F in this number system. The base of hexadecimal number system is 16, because it has 16 alphanumeric values. Here A is 10, B is 11, C is 12, D is 13, E is 14 and F is 15. Most popular number systems Used In Computer System And Mathematics Also
  • 31. S o m e R e f e r e n c e s Work behind en.wikipedia.org www.archimedes-lab.org www.math.chalmers.se www.slideshare.net www.google.com translate.google.com www.mathsisfun.com www.youtube.com www.purple-math.com www.whatis.techtarget.com www.basic-mathematics.com