Class 6 - Mathematics : Playing with Numbers
Exercise : 3.1
Top Block 1
NCERT Solutions Class 6 Mathematics Playing with Numbers Ex 3.1
1. Write all the factors of the following numbers:
(a) 24, (b) 15, (c) 21, (d) 27, (e) 12, (f) 20 , (g) 18, (h) 23, (i) 36
Answer :
(a) 24 = 1 x 24 = 2 x 12 = 3 x 8 = 4 x 6 = 6 x 4
∴ Factors of 24 = 1, 2, 3, 4, 6, 12, 24
(b) 15 = 1 x 15 = 3 x 5 = 5 x 3
∴ Factors of 15 = 1, 3, 5, 15
(c)21 = 1 x 21 = 3 x 7 = 7 x 3
∴ Factors of 21 = 1, 3, 7, 21
(d)27 = 1 x 27 = 3 x 9 = 9 x 3
∴ Factors of 27 = 1, 3, 9, 27
(e)12 = 1 x 12 = 2 x 6 = 3 x 4 = 4 x 3
∴ Factors of 12 = 1, 2, 3, 4, 6, 12
(f)20 = 1 x 20 = 2 x 10 = 4 x 5 = 5 x 4
∴ Factors of 20 = 1, 2, 4, 5, 10, 20
(g)18 = 1 x 18 = 2 x 9 = 3 x 6
∴ Factors of 18 = 1, 2, 3, 6, 9, 18
(h)23 = 1 x 23
∴ Factors of 23 = 1, 23
(i)36 = 1 x 36 = 2 x 18 = 3 x 12 = 4 x 9 = 6 x 6
∴ Factors of 36 = 1, 2, 3, 4, 6, 9, 12, 18, 36
2. Write first five multiples of: (a) 5, (b) 8, (c) 9
Answer :
(a) 5 x 1 = 5, 5 x 2 = 10, 5 x 3 = 15, 5 x 4 = 20, 5 x 5 = 25
∴ First five multiples of 5 are 5, 10, 15, 20, 25.
(b) 8 x 1 = 8, 8 x 2 = 16, 8 x 3 = 24, 8 x 4 = 32, 8 x 5 = 40
∴ First five multiples of 8 are 8, 16, 24, 32, 40.
(c) 9 x 1 = 9, 9 x 2 = 18, 9 x 3 = ,27, 9 x 4 = 36, 9 x 5 = 45
∴ First five multiples of 9 are 9, 18, 27, 36, 45.
Mddle block 1
3.Match the items in column 1 with the items in column 2:
| Column A | Column B |
|---|---|
| 1. 35 | A. Multiple of 8 |
| 2. 15 | B. Multiple of 7 |
| 3. 16 | C. Multiple of 5 |
| 4. 4 | D. Factor of 30 |
| 5. 20 | E. Factor of 20 |
Answer :
| Column A | Column B |
|---|---|
| 1. 35 | B. Multiple of 7 |
| 2. 15 | D. Factor of 30 |
| 3. 16 | A. Multiple of 8 |
| 4. 4 | E. Factor of 20 |
| 5. 20 | C. Multiple of 5 |
4.Find all the multiples of 9 up to 100.
Answer :
Multiples of 9 up to 100 are:
9, 18, 27, 36, 45, 54, 63, 72, 81, 90, 99
