Page 153 - New Medley 3 Semester 1

EXERCISE 4.9

Fill in the blanks.

1. 7116 × 1 =

2. 3372 × = 3372

3. × 1 = 4332

4. 5236 × 1219 = × 5236

5. 6453 × = 3467 × 6453

6. × 7162 = 7162 × 2316

7. 8315 × 5315 = 5315 ×

8. 9114 × 0 =

9. 1162 × = 0
10. (2341 × 3336) × 3512 = 2341 × ( × )

11. (4212 × 1343) × 8451 = × ( × 8451)
12. ( × ) × 1312 = 5634 × (4246 × 1312)

13. (6123 × ) × = 6123 × (2412 × 7534)

Estimating Product

Mr. Clark bought 81 packets each containing 29 pencils.

Let us make an estimate as to how many pencils did he buy by rounding
to nearest tens.

81 rounds to 80 and 29 rounds to 30.

80 × 30 = 2400

Mr. Clark nearly bought 2400 pencils.

Example 12: Estimate 87 × 59 by rounding to nearest tens.

Solution: Rounding off to nearest tens

87 is rounded off to 90

59 is rounded off to 60

Estimate product: 90 × 60 = 5400

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