Chapter 3: Playing with Number

Chapter 4:Basic Gemetrical Idea

Chapter 5:Understanding Elementry Shapes

Playing With Numbers

(a) 24 (b) 15 (c) 21 (d) 27 (e) 12 (f) 20 (g) 18 (h)23 (i) 36

(a) Factors of 24 are:

24 = 1 x 24 = 2 x 12 = 3 x 8 = 4 x 6

The factors of 24 are: 1, 2, 3, 4, 6, 8, 12 and 24.

(b) Factors of 15 are:

15 = 1 x 15 = 3 x 5

All the factors of 15 are: 1, 3, 5 and 15.

(c) Factors of 21 are:

21 = 1 x 21 = 3 x 7

the factors of 21 are: 1, 3, 7 and 21.
(d) Factors of 27 are:

27 = 1 x 27= 3 x 9.

The factors of 27 are: 1, 3, 9 and 27.

(e) Factors of 12 are:

12 = 1 x 12= 2 x 6= 3 x 4

The factors of 12 are: 1, 2, 3, 4, 6 and 12.

(f) Factors of 20 are:

20 = 1 x 20= 2 x 10= 4 x 5

The factors of 20 are: 1, 2, 4, 5, 10 and 20.

(g) Factors of 18 are:

18 = 1 x 18= 2 x 9= 3 x 6

The factors of 18 are: 1, 2, 3, 6, 9 and 18.

(h) Factors of 23 are:

23 = 1 x 23

The factors of prime number 23 are: 1 and 23.

(i) Factors of 36 are:

36 = 1 x 36= 2 x 18= 3 x 12= 4 x 9= 6 x 6
The factors of 36 are: 1, 2, 3, 4, 6, 9, 12, 18 and 36.

(a)5 (b) 8 (c) 9

5 x 1 = 5 ,5 x 2 = 10,5 x 3 = 15,5 x 4 = 20 ,5 x 5 = 25

multiples of 5 are: 5, 10, 15, 20 and 25.

(b) First five multiples of 8 are:

8 x 1 = 8 ,8 x 2 = 16 ,8 x 3 = 24 ,8×4 = 32 ,8 x 5 = 40

multiples of 8 are: 8, 16, 24, 32 and 40.

(c) First five multiples of 9 are:

9 x 1 = 9 ,9 x 2 = 18,9 x 3 = 27, 9 x 4 = 36 ,9 x 5 = 45

multiples of 9 are: 9,18, 27, 36 and 45

[ii] 35

[iii] 35

[iv] 35

[v] 35

[b] Multiple of 7

[c] Multiple of 70

[d] Factor of 30

[e] Factor of 50

[f] Factor of 20

[ii] 15

[iii] 16

[iv] 20

[v] 25

[d] Factor of 30

[a] Multiple of 8

[f] Factor of 20

[e] Factor of 50