Page 69 - Start Up Mathematics_4

(b) 756 × 214 (c) 3,245 × 927
Carry over of Carry over of → 2 4 4
1 1 ← (756 × 200) (3,245 × 900) 1 ← Carry over of
2 2 ← Carry over of
3
1
3
7 5 6 (756 × 4) Carry over of → 3 2 4 5 (3,245 × 20)
(3,245 × 7)
× 2 1 4 × 9 2 7
3 0 2 4 ← (756 × 4) 2
1 7 5 6 0 ← (756 × 10) 2 2 7 1 5 ← (3,245 × 7)
+ 1 5 1 2 0 0 ← (756 × 200) 1 1 6 4 9 0 0 ← (3,245 × 20)
1 6 1 7 8 4 ← Product + 2 9 2 0 5 0 0 ← (3,245 × 900)
3 0 0 8 1 1 5 ← Product

So, 756 × 214 = 1,61,784. So, 3,245 × 927 = 30,08,115.

Multiplication with Zero in the Multiplier A Challenge!

Example 6: Multiply 230 by 40. A queen bee lays 1,500
1 eggs in a day! How many
Solution: 2 3 0 ← Write these two zeros in eggs will it lay in 5 days?
× 4 0 the product.

9 2 0 0 Then multiply 23 by 4. 23 × 4 = 92
Write 92 before the two zeros.

So, 230 × 40 = 9,200.
Example 7: Multiply 428 by 305.

2 Quick Tip
1 4
Solution: 4 2 8 When there is a zero in any other

× 3 0 5 place but ones in the
multiplier, we leave it and
2 1 4 0 ← (428 × 5)
1 multiply by the next digit
+ 1 2 8 4 0 0 ← (428 × 300) of the multiplier.

1 3 0 5 4 0

Since the digit in the tens place of the multiplier is 0, the step is left out as
428 × 0 tens will give 0 as the product.

EXERCISE 5.6

Find the product.

(a) 93 × 215 (b) 68 × 137 (c) 807 × 114 (d) 790 × 800
(e) 1,326 × 204 (f) 4,906 × 520 (g) 93 × 182 (h) 34 × 205
(i) 76 × 326 (j) 158 × 720 (k) 867 × 412 (l) 753 × 123

(m) 4,070 × 960 (n) 8,973 × 602 (o) 1,596 × 348 (p) 937 × 406

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