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 (viii) 99880
(ix) 12796 (x) 55555
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 (viii) 99880
(ix) 12796 (x) 55555
We know that if a
number has its unit’s place digit as a, then its square
will end with the unit digit of the multiplication a ×
a.
(i) 81
Since
the given number has its unit’s place digit as 1, its square
will end with the unit digit of the multiplication (1 ×1 = 1)
i.e., 1.
(ii) 272
Since
the given number has its unit’s place digit as 2, its square
will end with the unit digit of the multiplication (2 ×
2 = 4) i.e., 4.
(iii) 799
Since
the given number has its unit’s place digit as 9, its square
will end with the unit digit of the multiplication (9 ×
9 = 81) i.e., 1.
(iv) 3853
Since
the given number has its unit’s place digit as 3, its square
will end with the unit digit of the multiplication (3 ×
3 = 9) i.e., 9.
(v) 1234
Since
the given number has its unit’s place digit as 4, its square
will end with the unit digit of the multiplication (4 ×
4 = 16) i.e., 6.
(vi) 26387
Since
the given number has its unit’s place digit as 7, its square
will end with the unit digit of the multiplication (7 ×
7 = 49) i.e., 9.
(vii) 52698
Since
the given number has its unit’s place digit as 8, its square
will end with the unit digit of the multiplication (8 ×
8 = 64) i.e., 4.
(viii) 99880
Since
the given number has its unit’s place digit as 0, its square
will have two zeroes at the end. Therefore, the unit digit of the
square of the given number is 0.
(xi) 12796
Since
the given number has its unit’s place digit as 6, its square
will end with the unit digit of the multiplication (6 ×
6 = 36) i.e., 6.
(x) 55555
Since
the given number has its unit’s place digit as 5, its square
will end with the unit digit of the multiplication (5 ×
5 = 25) i.e., 5.
We know that if a number has its unit’s place digit as a, then its square will end with the unit digit of the multiplication a × a.
(i) 81
Since the given number has its unit’s place digit as 1, its square will end with the unit digit of the multiplication (1 ×1 = 1) i.e., 1.
(ii) 272
Since the given number has its unit’s place digit as 2, its square will end with the unit digit of the multiplication (2 × 2 = 4) i.e., 4.
(iii) 799
Since the given number has its unit’s place digit as 9, its square will end with the unit digit of the multiplication (9 × 9 = 81) i.e., 1.
(iv) 3853
Since the given number has its unit’s place digit as 3, its square will end with the unit digit of the multiplication (3 × 3 = 9) i.e., 9.
(v) 1234
Since the given number has its unit’s place digit as 4, its square will end with the unit digit of the multiplication (4 × 4 = 16) i.e., 6.
(vi) 26387
Since the given number has its unit’s place digit as 7, its square will end with the unit digit of the multiplication (7 × 7 = 49) i.e., 9.
(vii) 52698
Since the given number has its unit’s place digit as 8, its square will end with the unit digit of the multiplication (8 × 8 = 64) i.e., 4.
(viii) 99880
Since the given number has its unit’s place digit as 0, its square will have two zeroes at the end. Therefore, the unit digit of the square of the given number is 0.
(xi) 12796
Since the given number has its unit’s place digit as 6, its square will end with the unit digit of the multiplication (6 × 6 = 36) i.e., 6.
(x) 55555
Since the given number has its unit’s place digit as 5, its square will end with the unit digit of the multiplication (5 × 5 = 25) i.e., 5.
