Question

Write down the unit digits of the following squares.
a) ${78}^2$
b) ${33}^2$
c) ${42}^2$
d) ${35}^2$

Answer 1

$8^2$ will be 64, so we will get 4 in unit digit.
$3^2$ will be 9, so unit digit will be 9.
$2^2$ will be 4, so unit digit will be 4.
Similarly you can find the unit digit for any square number by just squaring the unit digit of the number whose square is to be found.