Question

S3. Find the units digit of the square of the following
numbers,
(a) 89
(b) 406
(c) 30,465
(d) 48,798
(e) 33
(f) 1,60,0001​

Answer 1

Answer:

(i) The square of 24=24×24. Here 4 is in the unit place.

Therefore, we have 4×4=16.∴6 is in the unit digit of square of 24.

(ii) The square of 78=78×78. Here, 8 is in the unit place.

Therefore, we have 8×8=64.∴4 is in the unit digit of square of 78

(iii) The square of 35=35×35. Here, 5 is in the unit place.

Therefore, we have 5×5=25.∴5 is in the unit digit of square of 35.

Answer 2

(a) 89 × 89 = 7921 , unit digit = 1

(b) unit digit = 6

(c) unit digit = 5

(d) unit digit = 4

(e) unit digit = 9

(f) unit digit = 1