Question

Write down the unit digits of the following:
(i) ${78}^2$
(ii) ${27}^2$
(iii) ${41}^2$
(iv) ${35}^2$
(v) ${42}^2$

Answer 1

(i) As we can see that at unit's place of $78$ is $8$ and square of $8$ is $64$.

So, the unit of digit ${78}^2$ will be $4$.

(ii) As we can see that at unit's place of $27$ is $7$ and square of $7$ is $49$.

So, the unit digit of ${27}^2$ will be $9$.

(iii) As we can see that at unit's place of $41$ is $1$ and square of $1$ is $1$.

So, the unit digit og ${41}^2$ will be $1$

(iv) As we can see that at unit's place of $35$ is $5$and square of $5$ is $25$.

So, the unit digit of ${35}^2$ will be $5$.

(v) As we can see that at unit's place of $42$ is $2$ and square of $2$ is $4$.

So, the unit digit of ${42}^2$ will be $4$.