Question

Write down the unit digits of the squares of the following numbers:
(i) $24$ (ii) $78$ (iii) $35$

Answer 1

(i) The square of $24=24\times 24$. Here $4$ is in the unit's place.
Therefore, we have $4\times 4=16.⟹6$ is the unit's digit of square of $24$.
(ii) The square of $78=78\times 78$. Here, $8$ is in the unit's place.
Therefore, we have $8\times 8=64.⟹4$ is the unit's digit of square of $78$
(iii) The square of $35=35\times 35$. Here, $5$ is in the unit's place.
Therefore, we have $5\times 5=25.⟹5$ is the unit's digit of square of $35$.