Q.3 Estimate the following products using general rule:

(a) 578 × 161

(b) 5281 × 3491

(c) 1291 × 592

(d) 9250 × 29

Make four more such examples.

(a) 578 × 161

(b) 5281 × 3491

(c) 1291 × 592

(d) 9250 × 29

Make four more such examples.

(a) 578 × 161

Rounding off by general rule

578 and 161 rounded off to 600 and 200 respectively

600×200= 120000

(b) 5281 × 3491

Rounding off by general rule

5281 and 3491 rounded off to 5000 and 3500 respectively

5000 × 3500 = 17500000

(c) 1291 × 592

Rounding off by general rule

1291 and 592 rounded off to 1300 and 600 respectively

1300 × 600 = 780000

(d) 9250 × 29

Rounding off by general rule

9250 and 29 rounded off to 9000 and 30 respectively

9000 × 30 = 270000
Four more examples are as follows

(a) 178 × 351

Rounding off by general rule

178 and 351 rounded off to 200 and 400 respectively

200×400= 80000

(b) 5571 × 871

Rounding off by general rule

5571 and 871 rounded off to 6000 and 900 respectively

6000 × 900 = 5400000

(c) 181 × 92

Rounding off by general rule

181 and 92 rounded off to 200 and 90 respectively

200 × 90 =18000

(d) 4150 × 69

Rounding off by general rule

4150 and 69 rounded off to 4000 and 70 respectively

4000 × 70 = 280000