Question

Estimate the following products using general rule:

$\text{(i)}578\times 161$

$\text{(ii)}1291\times 592$

Answer 1

$\text{(i)}578\times 161$

Rounding off by general rule,
578 and 161 rounded off to 600 and 200, respectively

600
$\times$ 200
______
120000
______

$\text{(ii)}1291\times 592$

Rounding off by general rule,
1291 and 592 rounded off to 1200 and 600, respectively

1300
$\times$ 600
______
780000
______