Introduction to Number Systems

1. YEAR 9 MATHEMATICS
2012

2. Expected Learning Outcome
By the end of this lesson I will recognise and
know the members of important sets of
numbers

3. DO NOW
• Sit at your allocated seat.
• Put your bags down next to your feet.
• Take out your equipment and math book.
• Draw a title page for whole numbers
• The title page should be neat, colourful
and have a border.

5. NUMBER PATTERNS AND SEQUENCES
Number sequences are numbers arranged according to a certain rule or pattern.
For example, 3, 7, 11, 15, 19,…….add 4 starting from three.
MULTIPLES
Multiples of a number is the
product of the number and
any whole number except
zero
PRIME NUMBERS
A prime number is a whole
number that can only be
divided exactly by itself and 1.
It has only 2 factors, 1 and
itself
FACTORS
The factors of a number divide
the number exactly without
leaving a remainder. The
factors of 4 are 1, 2, and 4
COMMON MULTIPLES
A number which is a multiple of
two or more numbers is called
a common multiple of these
numbers.
PRIME FACTORS
Prime factors of a number are
factors of the number which
are prime numbers.
COMMON FACTORS
A number which is a factor
Of two or more numbers is
called a common factor
LOWEST COMMON
MULTIPLE (LCM)
The LCM of 2 or more numbers is the
smallest common multiple of the
numbers
HIGHEST COMMON
FACTOR (HCF)
The HCF of 2 or more numbers
is the largest common factor of
these numbers

6. Sets of Numbers
AO: use a range of strategies when operating with whole numbers
and know the relative size and place value of these numbers
List all the differences and similarities that you can see between 16 and 61
What do we call the number system we use today?
(Hindu Arabic number system.)
List the ten basic symbols used to represent our number system?
(0,1,2,3,4,5,6,7,8,9)
Write each symbol in words.
(zero, one two, three, four, five, six, seven, eight, nine.)
These ten symbols or figures are called d_ _ _ t _
digits
Our whole number system is based on how many digits?
Whole numbers consist of : 0,1,2,3,4,5,6,7,8,9……………. What do these dots mean to you?
The pattern is continued

7. What are other main sets of numbers apart from whole numbers?
Symbol Set of Numbers Examples
N Natural Numbers { 1, 2, 3, 4, 5, 6, ……….}
W Whole Numbers { 0, 1 2, 3, 4, 5, 6, ……..}
I Integers { ……-3, -2, -1, 0, 1, 2, 3, ……}
Q Rational
Numbers
This set includes all the numbers listed above
including fractions like It does
not include numbers that can not be written as
fractions.
Q’ Irrational
Numbers
, 1
8
, 1
2
, 3
3
7
3
The set of numbers that can not be expressed or
written as fractions. For example,
R Real Numbers This set consists of all the numbers listed above.
This means it is the universal set. It includes
every number you can think of.
What is the difference between Natural Numbers and Whole Numbers?
What is the difference between Whole Numbers and Integers?
Which is the largest number system?
Draw a diagram to illustrate the relative size of the number systems