Question

EXERCISE 6.1

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) 26387-
(vii) 52698
(vii) 99880
(ix) 12796
(x) 55555-​

Answer 1

Unit digit of a square of a number is equal to the unit digit of square of unit digit of that number.
So,
(i)81
- Unit digit of square of 81
will be 1
.
(ii)272
- Unit digit of square of 272
will be 4
.
(iii)799
- Unit digit of square of 799
will be 1
.
(iv)3853
- Unit digit of square of 3853
will be 9
.
(v)1234
- Unit digit of square of 1234
will be 6
.
(vi)26387
- Unit digit of square of 26387
will be 9
.
(vii)52698
- Unit digit of square of 52698
will be 4
.
(viii)99880
- Unit digit of square of 99880
will be 0
.
(ix)12796
- Unit digit of square of 12796
will be 6
.
(x)55555
- Unit digit of square of 55555
will be 5

.