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


Rounding off by general rule,


598 rounds off to 600


161 rounds off to 200,


So,


= 600×200 = 120000


(b) 5281×3491


Rounding off by the general rule,


5281 rounds off to 5000


3491 rounds off to 3000


So,


= 5000×3000


= 15000000


(c) 1291×592


Rounding off by general rule,


9250 rounds off to 1000


592 rounds off to 600


So,


= 1000×600


= 600000


(d) 9250×29


Rounding off by general rule,


9250 rounds off to 9000


29 rounds off to 30


So,


= 9000 × 30


= 270000


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