Page 68 - Start Up Mathematics_3

EXERCISE 5.3

1. Find the following products.

H T O H T O H T O
(a) (b) (c)
1 1 2 3 0 1 2 1 3

× 4 × 2 × 3

Th H T O Th H T O Th H T O
(d) (e) (f)
3 6 2 7 5 8 5 0 4

× 4 × 6 × 9

2. Write the numbers in columns and find the product.
(a) 932 × 6 (b) 471 × 5 (c) 784 × 8 (d) 672 × 9 (e) 553 × 7

(f) 608 × 5 (g) 892 × 8 (h) 734 × 6 (i) 198 × 9 (j) 932 × 4

Multiplication by 10, 100 and 1000

We know that if we multiply a number by another number ending with zero, the
product always ends with zero.

Multiplication by 10

To multiply a number by 10, just write the number and put one zero at the end of it.
For example, 9 × 10 = 90 28 × 10 = 280 137 × 10 = 1370

To multiply a number by 20, 30, 40, 50 and so on, write 0 at the end, multiply the
number by the remaining digit(s) and write the product before 0.

For example, 64 × 2 0 = 1280 238 × 5 0 = 11900
6 4 1 4

× 2 2 3 8
1 2 8 × 5
1 1 9 0

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