Question
What will be the “one’s digit” in the square of the following numbers?
(i) 1234 (ii) 26387 (iii) 52698
(iv) 99880 (v) 21222 (vi) 9106
Solution
(i) ∵ Ending digit = 4 and 42 = 16
∴ (1234) will have 6 as the one’s digit.
(ii) ∵ Ending digit is 7 and 72 = 49
∴ (26387)2 will have 9 as the one’s digit.
(iii) ∵ Ending digit is 8, and 82 = 64
∴ (52692)2 will end in 4.
(iv) ∵ Ending digit is 0.
∴ (99880)2 will end in 0.
(v) ∵ 22 = 4
∴ Ending digit of (21222)2 is 4.
(vi) ∵ 62 = 36
∴ Ending digit of (9106)2 is 6.
