Question

What is the square of the number $218$ using direct multiplication method?

Answer 1

We can write ${218}^2=(200+18{)}^2$

Using $(a+b{)}^2=a(a+b)+b(a+b)$
Here $a=200,b=18$
Therefore, ${218}^2=200(200+18)+18(200+18)$

$=$ ${200}^2+3600+3600+{18}^2$
$=40000+7200+324$
$=47524$