Question

Solve the problem using direct multiplication method to find the square of $412$.

Answer 1

We can write ${412}^2=(400+12{)}^2$

Using $(a+b{)}^2=a(a+b)+b(a+b)$
Here $a=400,b=12$
Therefore, ${412}^2=400(400+12)+12(400+12)$
$=$ ${400}^2+4800+4800+{12}^2$
$=160000+9600+144$
$=169744$