Question

Find the approximate and actual cost of 21 bottles of oil, if one bottle costs ₹205

• A. 4,000, 4,305
• B. 4,000, 4,205
• C. 6,000, 6,905
• D. 6,000, 6,105

Answer 1

The correct option is A 4,000, 4,305

$205\times 21$ is nearly $200\times 20.$
$200\times 20=4,000$
$\therefore$ On guessing, $205\times 21$ is nearly $4,000$.

$205\times 21$ can be calculated using boxes.

$205\times 21=4000+100+200+5=4,305$
$\therefore$ On calculating, $205\times 21=4,305$.