Estimate the following products using general rule:
(a) 578 × 161 (b) 5281 × 3491
(c) 1291 × 592 (d) 9250 × 29
(a) 578 × 161
Rounding off by general rule, 578 and 161 may be rounded off to 600 and 200 respectively.
(b) 5281 × 3491
Rounding off by general rule, 5281 and 3491 may be rounded off to 5000 and 3000 respectively.
(c) 1291 × 592
Rounding off by general rule, 1291 and 592 may be rounded off to 1000 and 600 respectively.
(d) 9250 × 29
Rounding off by general rule, 9250 and 29 may be rounded off to 9000 and 30 respectively.