Question

Solve the problem using direct multiplication method to find the square of $73$.

Answer 1

We can write ${73}^2=(70+3{)}^2$

Using $(a+b{)}^2=a(a+b)+b(a+b)$
Here $a=70,b=3$
Therefore, ${73}^2=70(70+3)+3(70+3)$
$=$ ${70}^2+210+210+3^2$
$=4900+420+9$
$=5329$