2. Numeration Systems
• Reason why numeration exist
• Bases of Numeration System
• Different Representation of Counting Numbers
• One-for-One Correspondence
• The Commonly used Number Systems Today
• Other Number Systems
• Modular Systems
• Conversion of Different Number Systems
• Arithmetic Operations of Different Number
Systems
3. Numeration Systems
• Structured methods or procedures for counting in order
to determine the total units in a collection.
• Consist of counting bases and some form of
representation.
example: base 2, base 8, base 10, base 16, etc.
• Numerals are symbols or groups of symbols that
represents a number.
example: the symbols 12, twelve, and XII are different
numerals that all represent the same number.
4. 3 Reasons why Numeration
Systems Exist
• To Identify numeration system identify people and property to
preserve confidentiality, increase security, and minimizes errors.
• To order define a person or unit’s order in a series.(ordinal-
first, second, third, etc. and cardinal- one, two, three, etc.)
• To Tally used to tally or total
to find out how many items or units are involved in a
calculation (addition, subtraction , multiplication ,
or division).
5. The concept of number has
two complementary aspects:
• Cardinal Numbering – It relies only on the principle of
mapping
• Ordinal Numeration – It requires both the technique
of pairing and the idea of succession.
6. The Bases Of Numeration
Systems
• The base of a numeration system is its frame of
reference or the starting point on which it grounds its
counting method.
• Many bases of numeration systems are founded
upon the most obvious and immediate things in a
person's visual field:(arms, hands, fingers, and toes.
• Common bases of numeration systems are the two
arms of a person (base 2 system), the fingers of one
hand (base 5 system), the fingers of both hands
(base 10 system), or the total of all a person’s
fingers and toes (base 20 system).
7. Principle Base of 2 (Binary
Principle)
• Was one of the most common numeration systems in
ancient times.
• Primitive people possessed this fundamental arithmetical
rule which allowed them to manipulate numbers far in
excess of four.
• To indicate a number like three or four, the person
says “two-and-one” or “two-and-two.” The number 10 is
indicated with “two-and-two-and-two-and-two-and-
two.” However, as a person counts to higher and higher
numbers in a base 2 system, it becomes harder and harder
to remember one’s place in the long string of twos.
• Have now been replaced by decimal (or base 10) systems.
9. Continuation..
• Everyone can see the sets of one, of two, and of
three, of four objects in the figure. But that’s about
the limit of our natural ability to numerate.
• Beyond four, quantities are vague, and our eyes
alone cannot tell us how many things they are.
10. Continuation..
• There are many traces of the ‘limit of four’ in different
languages and cultures.
• For Example: Romans gave ‘ordinary names’ to the
first four of their sons but the fifth and other sons were
named only by a numerical: Quintus (Fifth), Sixtus
(Sixth), Septimus (Seventh), so on.
• Another example is the Roman calendar where the
first four months had names but the fifth to tenth are
referred to by their order names: Quintilis, Sextilis,
September, October, etc.
11. Base 10 Numeration System
• The base 10 or decimal system has now spread
throughout the world and is the most commonly
used numeration system today.
12. Different Representation of Counting
Numbers
• People began by counting the first nine numbers by
placing in sequence the corresponding number of
strokes, circles or other similar representing ‘one’ more
or less:
18. “One-for-One
Correspondence”
• a device in which both the prehistory of
arithmetic and the dominant mode of
operation in all contemporary “hard” science
• allows even the simplest of minds to compare
two collections of beings or things, of the
same kind or not, without calling an ability to
count in numbers.
30. 30
Number Systems
Base 2: The Binary Number System
Base 8: The Octal Number System
Base 10: The Decimal Number System
Base 16: The Hexadecimal Number System
31. 31
Number Base
• What is a number base?
A number base is a specific collection of
symbols on which a number system can be built.
• The number base familiar to us is base 10, upon
which the decimal number system is built. There
are ten symbols - 0 to 9 - used in the decimal
system.
32. 32
Place Value
• What is the concept of place value?
Place value means that the value of a digit
in a number depends not only on its own natural
value but also on its location in the number.
It is used interchangeably with the term
positional notation.
• Place value tells us that the two 4s in the
number 3474 have different values, that is, 400
and 4, respectively.
33. 33
A Review of the Decimal Number System
• The word “decimal” comes from the Latin word
decem, meaning ten.
• Thus, the number base of the decimal number
system is base 10.
• Since it is in base 10, ten symbols are used in
the decimal number system.
{0,1,2,3,4,5,6,7,8,9}
• This means that only the digits in the above set
can be used for each position in every place
value in a given decimal number.
34. 34
A Review of the Decimal Number System
• Note that the highlighted place value can be
filled by the digits in the set {0,1,2,3,4,5,6,7,8,9}.
• Thus, it can be increased by 1 until it reaches -
• At this point, the symbols that can be used to fill
the highlighted position has been exhausted.
Increasing it further causes a shift in place value,
and resets the initial place value to zero. Thus -
2 7 0
2 7 9
2 8 0
35. 35
A Review of the Decimal Number System
• Case Study: 3474
• Using place values, the number 3474 is
understood to mean,
3000 + 400 + 70 + 4 = 3474
This can also be expressed as –
(3x1000) + (4x100) + (7x10) + 4 = 3474
Note that each digit is multiplied by powers of
10, so that the above is equal to –
(3x103) + (4x102) + (7x101) + (4x100) = 3474
Note that the rightmost exponent starts from
zero and increases by 1 as the place value
increases.
Hence, the decimal number system is said to be
in base 10.
36. 36
Base 2: The Binary Number System
• The word “binary” comes from the Latin word
bis, meaning double.
• Thus, the number base of the binary number
system is base 2.
• Since it is in base 2, two symbols are used in the
binary number system.
{0,1}
• This means that only the digits in the above set
can be used for each position in every place
value in a given binary number.
37. 37
Base 2: The Binary Number System
• Note that the highlighted place value can be
filled by the digits in the set {0,1}.
• Thus, it can be increased by 1 until it reaches -
• At this point, the symbols that can be used to fill
the highlighted position has been exhausted.
Increasing it further causes a shift in place value,
and resets the initial place value to zero. Thus -
1 1 0
1 1 1
1 1 0
0
0
1
38. 38
Base 2: The Binary Number System
• To avoid confusion, one should write a binary
number with base 2 as its subscript whenever
necessary.
• Thus, the binary number 10110 should be
written as -
101102
• It should be read as “one-zero-one-one-zero
base two” and NOT “ten-thousand one-hundred
ten” since each phrase denotes an entirely
different number.
39. 39
Base 2: The Binary Number System
• Case Study: 101102
• We know that the decimal number 3474 can be
expressed as powers of 10 –
(3x103) + (4x102) + (7x101) + (4x100) = 347410
• In the same manner, the binary number 101102
can be expressed as powers of 2 –
(1x24) + (0x23) + (1x22) + (1x21) + (0x20) = 2210
Note that the rightmost exponent starts from
zero and increases by 1 as the place value
increases.
Hence, the binary number system is said to be in
base 2.
40. 40
Base 8: The Octal Number System
• The word “octal” comes from the Greek word
oktõ, meaning eight.
• Thus, the number base of the octal number
system is base 8.
• Since it is in base 8, eight symbols are used in
the octal number system.
{0,1,2,3,4,5,6,7}
• This means that only the digits in the above set
can be used for each position in every place
value in a given octal number.
41. 41
Base 8: The Octal Number System
• Note that the highlighted place value can be
filled by the digits in the set {0,1,2,3,4,5,6,7}.
• Thus, it can be increased by 1 until it reaches -
• At this point, the symbols that can be used to fill
the highlighted position has been exhausted.
Increasing it further causes a shift in place value,
and resets the initial place value to zero. Thus -
3 6 0
3 6 7
3 7 0
42. 42
Base 8: The Octal Number System
• To avoid confusion, one should write an octal
number with base 8 as its subscript whenever
necessary.
• Thus, the octal number 72143 should be written
as -
721438
• It should be read as “seven-two-one-four-three
base eight” and NOT “seventy two-thousand
one-hundred forty three” since each phrase
denotes an entirely different number.
43. 43
Base 8: The Octal Number System
• Case Study: 721438
• We know that the decimal number 3474 can be
expressed as powers of 10 –
(3x103) + (4x102) + (7x101) + (4x100) = 347410
• In the same manner, the octal number 721438
can be expressed as powers of 8 –
(7x84) + (2x83) + (1x82) + (4x81) + (3x80) = 2979510
Note that the rightmost exponent starts from
zero and increases by 1 as the place value
increases.
Hence, the octal number system is said to be in
base 8.
44. 44
Base 16: The Hexadecimal Number System
• The word “hexadecimal” is a combination of the
Greek word hex, meaning six and the Latin word
decem, meaning ten.
• Thus, the number base of the hexadecimal
number system is base 16.
• Since it is in base 16, sixteen symbols are used
in the hexadecimal number system.
{0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,F}
• This means that only the digits in the above set
can be used for each position in every place
value in a given hexadecimal number.
45. 45
Base 16: The Hexadecimal Number System
• Note that the highlighted place value can be
filled by the digits in the set
{0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,F}.
• Thus, it can be increased by 1 until it reaches -
• At this point, the symbols that can be used to fill
the highlighted position has been exhausted.
Increasing it further causes a shift in place value,
and resets the initial place value to zero. Thus -
A 3 0
A 3 F
A C
3
B
B
0
46. 46
Base 16: The Hexadecimal Number System
• To avoid confusion, one should write a
hexadecimal number with base 16 as its
subscript whenever necessary.
• Thus, the hexadecimal number B23C
should be written as -
B23C16
• It should be read as “b-two-three-c base
sixteen”.
47. 47
Base 16: The Hexadecimal Number System
• Case Study: B23C16
• We know that the decimal number 3474 can be
expressed as powers of 10 –
(3x103) + (4x102) + (7x101) + (4x100) = 347410
• In the same manner, the hexadecimal number
B23C16 can be expressed as powers of 16 –
(11x163) + (2x162) + (3x161) + (12x160) = 4562810
Note that the rightmost exponent starts from
zero and increases by 1 as the place value
increases.
Hence, the hexadecimal number system is said
to be in base 16.
49. 49
Comparative Values: Bases 10, 2, 8, 16
Base 10 Base 2 Base 8 Base 16
Decimal Binary Octal Hexadecimal
9 1001 11 9
10 1010 12 A
11 1011 13 B
12 1100 14 C
13 1101 15 D
14 1110 16 E
15 1111 17 F
16 10000 20 10
17 10001 21 11
50. Other Number Systems
• Base 3: The Ternary Number System
• Base 4: The Quaternary Number System
• Base 5: The Quinary Number System
• Base 6: The Senary Number System
• Base 7: The Septenary Number System
51. Base 3 Number System
• The Ternary numeral system.
• The base is 3.
• a ternary digit is called a trit (trinary digit). One trit is
equivalent to log2 3 (about 1.58496) bits of information.
• There are Three "digits": 0,1, 2.
• Positions correspond to integer powers of three,
starting with power 0 at the rightmost digit, and
increasing right to left.
• The digit placed at a position shows how many times
that power of three is included in the number.
52. Base 4 Number System
• Called the Quaternary Number System
• The base is four.
• There are four "digits": 0,1, 2, 3 .
• Positions correspond to integer powers
of four, starting with power 0 at the
rightmost digit, and increasing right to left.
• The digit placed at a position shows how
many times that power of four is included
in the number.
53. Base 5 Number System
• Called the Quinary number system
• The base is five.
• There are five "digits": 0,1, 2, 3, 4 .
• Positions correspond to integer powers
of five, starting with power 0 at the
rightmost digit, and increasing right to left.
• The digit placed at a position shows how
many times that power of five is included
in the number.
54. Base 6 Number System
• Called the Senary, heximal or seximal number
system
• The base is six.
• There are six "digits": 0,1, 2, 3, 4,5.
• Positions correspond to integer powers of six, starting
with power 0 at the rightmost digit, and increasing right
to left.
• The digit placed at a position shows how many times
that power of six is included in the number.
55. Base 7 Number System
• Called the Septenary number system
• The base is seven.
• There are seven "digits": 0,1, 2, 3, 4,5,6.
• Positions correspond to integer powers
of seven, starting with power 0 at the
rightmost digit, and increasing right to left.
• The digit placed at a position shows how
many times that power of seven is
included in the number.
56. Modular Arithmetic
• Modular arithmetic is a
special type of arithmetic
that involves only integers.
• Sometimes, we are only
interested in what the
remainder is when we
divide A by B.
• For these cases there is an
operator called the modulo
operator (abbreviated as
mod).
• Using the same A, B, Q,
and R as sample below,
we would have:
• A mod B = R is same as
A modulo B is equal to R.
Where B is referred to as
the modulus.
58. Example:
• The remainders start at
0 and increases by 1
each time, until the
number reaches one
less than the number
we are dividing by. After
that, the
sequence repeats.