Page 33 - Start Up Mathematics_5

Example 15: Multiply 78,493 by 1,562.

Solution: We usually write the bigger number as multiplicand and the smaller as
multiplier.

Carry over of (78,493 × 500) → 4 2 4 1 Carry over of

5 2 5 1 → (78,493 × 60)
Carry over of (78,493 × 2) → 1 1

7 8 4 9 3

× 1 5 6 2

2 2 2 1
1 1 5 6 9 8 6 → (78,493 × 2)

2 4 7 0 9 5 8 0 → (78,493 × 60)

3 9 2 4 6 5 0 0 → (78,493 × 500)

+ 7 8 4 9 3 0 0 0 → (78,493 × 1,000)
1 2 2 6 0 6 0 6 6

Example 16: Find the product of 8,920; 306 and 1,754.

Solution: Using the associative property of multiplication, we can write this product as
(8,920 × 1,754) × 306.

Step 1: Multiply 8,920 by 1,754.

Carry over of (8,920 × 700) → 6 1 Carry over of

4 1 → (8,920 × 50)
Carry over of (8,920 × 4) → 3

8 9 2 0
× 1 7 5 4

1

1 3 5 6 8 0 → (8,920 × 4)

1 4 4 6 0 0 0 → (8,920 × 50)

6 2 4 4 0 0 0 → (8,920 × 700)
+ 8 9 2 0 0 0 0 → (8,920 × 1,000)

1 5 6 4 5 6 8 0

25