Page 68 - Start Up Mathematics_4

EXERCISE 5.5

Find the product.
(a) 76 × 43 (b) 92 × 38 (c) 145 × 39 (d) 254 × 67

(e) 608 × 42 (f) 4,652 × 19 (g) 3,510 × 80 (h) 9,922 × 76
(i) 104 × 18 (j) 453 × 62 (k) 198 × 74 (l) 2,132 × 38

(m) 9,254 × 17 (n) 8,007 × 56 (o) 3,965 × 85 (p) 4,280 × 90

Multiplication by a 3-Digit Number

Example 5: Multiply (a) 92 by 134 (b) 756 by 214 (c) 3,245 by 927

Solution: (a) 92 × 134

9 2 Step 1: Multiply the multiplicand by the digit in the ones place
× 1 3 4 of the multiplier. 92 × 4 ones = 92 × 4 = 368

3 6 8

9 2 Step 2: Multiply the multiplicand by the digit in the tens place

× 1 3 4 of the multiplier. 92 × 3 tens = 92 × 30 = 2,760

3 6 8 Write below 368.
2 7 6 0

9 2 Step 3: Multiply the multiplicand by the digit in the hundreds

× 1 3 4 place of the multiplier. 92 × 1 hundred = 92 × 100 =
3 6 8 9,200.
Write below 2,760.
2 7 6 0
9 2 0 0

9 2 Step 4: Add the products obtained in steps 1, 2 and 3.
× 1 3 4

1
3 6 8
1 Maths Fun
2 7 6 0
+ 9 2 0 0 What did one Maths book
say to the other Maths book?
1 2 3 2 8

So, 92 × 134 = 12,328.

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