NCERT Solutions for Class Six Maths Chapter Score for students to read and solve all Mathematics questions, we are providing NCERT Solutions Class Six Key Chapter 3 questions to all of you students, through which you all You will be able to find all the solutions of NCERT Class Six Chapter 3 Exercise 3.1

## NCERT Solutions for Class 6 Maths Chapter 3 Playing With Numbers Ex 3.1

Question 1.

**Write all the factors of the following numbers:**

**(i)** 24

**(ii)** 15

**(iii)** 21

**(iv)** 27

**(v)** 12

**(vi)** 20

**(vii)** 18

**(viii)** 23

**(ix)** 36.

Solution :

**(i)** 24

24 = 1 × 24

24 = 2 × 12

24 = 3 × 8

24 = 4 × 6

24 = 6 × 4

Stop here, because 4 and 6 have occurred earlier. Thus, all the factors of 24 are 1, 2, 3, 4, 6, 8, 12 and 24.

**(ii)** 15

15 = 1 × 15

15 = 3 × 5

15 = 5 × 3

Stop here, because 3 and 5 have occurred earlier. Thus, all the factors of 15 are 1, 3, 5 and 15.

**(iii)** 21

21 = 1 × 21

21 = 3 × 7

21 = 7 × 3

Stop here, because 3 and 7 have occurred earlier. Thus, all the factors of 21 are 1, 3, 7 and 21.

**(iv)** 27

27 = 1 × 27

27 = 3 × 9

27 = 9 × 3

Stop here, because 3 and 9 have occurred earlier. Thus, all the factors of 27 are 1, 3, 9 and 27.

**(v)** 12

12 = 1 × 12

12 = 2 × 6

12 = 3 × 4

12 = 4 × 3

Stop here, because 3 and 4 have occurred earlier. Thus, all the factors of 12 are 1,2,3,4,6 and 12.

**(vi)** 20

20 = 1 × 20

20 = 2 × 10

20 = 4 × 5

20 = 5 × 4

Stop here, because 4 and 5 have occurred earlier. Thus, all the factors of 20 are 1, 2, 4, 5, 10 and 20.

**(Vii)** 18

18 = 1 × 18

18 = 2 × 9

18 = 3 × 6

18 = 6 × 3

Stop here, because 3 and 6 have occurred earlier. Thus, all the factors of 18 are 1,2,3,6,9 and 18.

**(viii)** 23

23 = 1 × 23

Thus, all the factors of 23 are 1 and 23.

**(ix)** 36

36 = 1 × 36

36 = 2 × 18

36 = 3 × 12

36 = 4 × 9

36 = 6 × 6

36 = 6 × 6

Stop here, because both the factors 6 and 6 have occurred earlier. Thus, all the factors of 36 are 1,2,3,4,6,9,12, 18 and 36.

Question 2.

**Write the first five multiples of:**

**(i)** 5

**(ii)** 8

**(iii)** 9.

Solution :

**(i)** 5

First, five multiples of 5 are 5 × 1, 5 × 2, 5 × 3, 5 × 4 and 5 × 5

i. e.,5, 10, 15, 20 and 25.

**(ii)** 8

First, five multiples of 8 are 8×1,8×2,8×3,8 × 4 and 8×5

i.e., 8, 16, 24, 32 and 40.

**(iii)** 9

First, five multiples of 9 are 9 × 1,9 × 2,9 × 3,9 × 4 and 9×5

i.e., 9, 18,27, 36 and 45.

Question 3.

Match the items in column 1 with the items in column 2 :

Solution :

Question 4.

Find all the multiples of 9 up to 100.

Solution :

**The multiples of 9 are**

9 × 1, 9 × 2, 9 × 3. 9 × 4, 9 × 5, 9 × 6, 9 × 7, 9 × 8, 9 × 9, 9 × 10, 9 × 11, 9 × 12……….

i.e.. 9, 18, 27, 36, 45, 54. 63, 72, 81, 90, 99, 108,

Thus, all the multiples of 9 up to 100 are 9, 18, 27, 36, 45, 54, 63, 72, 81, 90 and 99.