1.What will be the unit digit of the squares of the following numbers?
(i) 81

(ii) 272

(iii) 799

(iv) 3853

(v) 1234

(vi) 20387

(vii) 52698

(viii) 99880

(ix) 12796

(x) 55555

As we know that unit's place is affected only by the unit’s place of the number of which square is seen. So we have: (i) Unit digit of \(81^2\) = 1 [Unit’s place=1 i.e, \(1 \times 1\) =1]
(ii) Unit digit of \(272^2\) = 4 [Unit’s place=2 i.e, \(2 \times 2\) =4]

(iii) Unit digit of \(799^2\) = 1 [Unit’s place=1 i.e, \(9 \times 9\) =1]

(iv) Unit digit of \(3853^2\) = 9 [Unit’s place=3 i.e, \(3 \times 3\) =9]

(v) Unit digit of \(1234^2\) = 6 [Unit’s place=4 i.e, \(4 \times 4\) =6]

(vi) Unit digit of \(26387^2\) = 9 [Unit’s place=7 i.e, \(7 \times 7\) =9]

(vii) Unit digit of \(52698^2 \)= 4 [Unit’s place=8 i.e, \(8 \times 8\) =4]

(viii) Unit digit of \(99880^2\) = 0 [Unit’s place=0 i.e, \(0 \times 0\) =0]

(ix) Unit digit of \(12796^2\) = 6 [Unit’s place=6 i.e, \(6 \times 6\) =6]

(x) Unit digit of \(55555^2\) = 5 [Unit’s place=5 i.e, \(5 \times 5\) =5]