1. Types of number even numbers A number that ends in 2, 4, 6, 8 or 0
factor A number which divides exactly into another number
integer A whole number
odd number A number ending in 1, 3, 5, 7 or 9
prime A number with exactly two factors, 1 and itself.
Square numbers These are made by multiplying a whole number by itself
Triangular numbers The number sequence made by the following pattern

2. Objectives
Recognise and use multiples, factors and primes
(less than 100); use simple tests for divisibility
Recognise the first few triangular numbers, squares
of numbers to at least 12 by 12
Recognise simple cubes.

3. Which is the odd one out? 14 25 36 44

4. Which is the odd one out? 2 3 4 5

5. Which is the odd one out? 49 16 64 21

6. Which is the odd one out?
231
154
324
489

7. Sorting Numbers
Sort the numbers into different groups using a mathematical criteria
Repeat using a different mathematical criteria.
How many different groups can you make?

8. Answers
Guess the Criteria
Group A
Group B
Group C
Group D
Group E

9. Answers
Guess the Criteria
Group A 11
Group B
Group C 55
Group D

10. Complete this grid
Even Numbers
Triangular Numbers
Square Numbers
Multiples of 5
Odd Numbers
Multiples of 3

11. D Cavill
2003

12. Why?
Justify your answer

13. 14, 36 and 44 are even numbers
25 is the only odd number

14. 2, 3 and 5 are prime numbers
4 is the only number that is not a prime number

15. 16, 49 and 64 are square numbers
21 is not a square number

16. 231, 324 and 489 are multiples of 3
231 ÷ 3 = 77
324 ÷ 3 = 108
489 ÷ 3 = 163
154 is not a multiple of 3

17. Guess the Criteria
Group A – Multiples of 2
Group B – Multiples of 3
Group C – Multiples of 5
Group D – Multiples of 7
Group E – Multiples of 11

18. Guess the Criteria
Group A – prime numbers 11
Group B – square numbers
Group C – triangular numbers 55
Group D – cube numbers