Page 50 - Fun with Mathematics 2

MULTIPLYING A 3-DIGIT NUMBER BY A 1-DIGIT NUMBER

Multiply 368 by 7.
Step 1. Multiply the ones digits.
H T O 8 × 7 = 56 = 5 tens + 6 ones
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5
3 6 8 Write 6 under the ones (O) column and carry
× 7 over 5 tens to the tens (T) column.
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Step 2. Multiply the tens digits. 6 × 7 = 2
4
2 5 7 6 Add all the tens: 2 tens + 5 tens = 7 tens
4
4
4 7 tens = hundreds + 7 tens
Write 7 under the tens (T) column and carry over
4 hundreds to the hundreds (H) column.
Step 3. Now, multiply the hundreds digits. 3 × 7 = 21
4
Add all the hundreds: 21 hundreds + hundreds
= 25 hundreds
Write 25 under the hundreds (H) column.
The product of 368 and 7 is 2576.

8 Multiply the following.

(a) H T O (b) H T O (c) H T O (d) H T O

1 2 4 2 1 3 2 1 1 1 1 1
× 2 × 3 × 4 × 5

(e) H T O (f) H T O (g) H T O (h) H T O

1 3 2 2 0 4 3 1 2 1 4 2

× 6 × 7 × 8 × 9

9 Write in the vertical form and multiply.

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(a) 213 × 2 (b) 315 × 3 (c) 123 × (d) 226 × 5

H T O H T O H T O H T O

× × × ×

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