Question

Find the square of $86$ without multiplication.

Answer 1

Solution: ${86}^2=86\times 86=7396$
To make calculations easy, use the following approach:
We know $86=(80+6)$
So, ${86}^2=(80+6{)}^2$

$={80}^2+2\times 80\times 6+6^2$
$=$ $6400+2\times 480+36=7396$