Question

Estimate the following products using general rule:
Make four more such examples.

$a)578\times 161$

Answer 1

Step 1 : Evaluate product by rounding off by general rule

Given, $578\times 161$
Rounding off by general rule
$578$ and $161$ rounded off to $600$ and $200$ respectively
$\therefore 578\times 161$
$=600\times 200=120000$

Step 2 : Make four more such examples

Four more examples are as follows
$i.391\times 1053$
Rounding off by general rule
$391$ and $1053$ rounded off to $400$ and $1000$ respectively
$391\times 1053=400\times 1000=4,00,000$

$ii.6725\times 1391$
Rounding off by general rule
$6725$ and $1391$ rounded off to $7000$ and $1000$ respectively
$6725\times 1391=7000\times 1000=70,00,000$

$iii.3848\times 9451$
Rounding off by general rule
$3848$ and $9351$ rounded off to $4000$ and $9000$ respectively
$3848\times 9451=4000\times 9000=3,60,00,000$

$iv.3309\times 7503$
Rounding off by general rule
$3309$ and $7503$ rounded off to $3000$ and $8000$ respectively
$3309\times 7503=3000\times 8000=2,40,00,000$