Question

The square of $43$ ends with the digit
$\left( A \right)\,\,9$
$\left( B \right)\,\,3$
$\left( C \right)\,\,4$
$\left( D \right)\,\,6$

Answer 1

Hint: We can easily find the last digit of the square of the given number by simply multiplying it two times. We can also find the last digit of the square of the given number if we know the last digit of the given number as $3$ in this question.

Complete step-by-step answer:
In the given question,
We know that if we multiply the given number two times, then we can find the end digit of the square of the given number.
Therefore,
$ \Rightarrow 43 \times 43 = 1849$
Therefore, the square of $43$ ends with the digit $9$.
We can also find the last digit of the square of $43$ without multiplying it two times.
As, we can see that $43$ ends with $3$. So, the square of $43$ ends with the square of the last digit of $43$, that is $3 \times 3 = 9$ .
Therefore, by this method also we can find the last digit of the square of $43$
So, the correct answer is “Option A”.

Note: Like a given question we can also find the end digit of the square of the given number. For example, if we want to find the end digit of the square of $22$, we can easily find it by squaring the last digit of $22$ i.e. 2 and we get $4$ as answer. But if we want to find the last digit of the square of a number ending with a value greater than $3$ then we have to consider the last digit of the square of the last digit of the given number.