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# 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

**Solution:**

(i) If a number has 1 or 9 in its unit digit, then its square ends with 1.

Since 81 has 1 as its unit digit, 1 will be the unit digit of its square. (1 × 1 = 1)

Similar Examples - 91, 721, 4321

(ii) If a number has either 2 or 8 as its unit digit, then its square ends with 4.

Since 272 has 2 as its unit digit, 4 will be the unit digit of its square. (2 × 2 = 4)

Similar Examples - 22, 2432, 147322

(iii) If a number has 1 or 9 in its unit digit, then its square ends with 1

Since 799 has 9 as its unit digit, 1 will be the unit digit of its square. (9 × 9 = 81)

(iv) If a number has either 3 or 7 as its unit digit, then its square number ends with 9.

Since 3853 has 3 as its unit digit, 9 will be the unit digit of its square. (3 × 3 = 9)

Similar Examples - 13, 433, 63

(v) If a number has either 4 or 6 as its unit digit, then its square ends with 6.

Since 1234 has 4 as its unit digit, 6 will be the unit digit of its square. (4 × 4 = 16)

Similar Examples - 14, 114, 484, 1594

(vi) If a number has either 3 or 7 as its unit digit, then its square number ends with 9.

Since 26387 has 7 as its unit digit, 9 will be the unit digit of its square. (7 × 7 = 49)

(vii) If a number has either 2 or 8 as its unit digit, then its square ends with 4.

Since 52698 has 8 as its unit digit, 4 will be the unit digit of its square. (8 × 8 = 64)

(viii) If a number has 0 as its unit digit, then its square ends with 0.

Since 99880 has 0 as its unit digit, 0 will be the unit digit of its square.

Similar Examples - 190, 1240, 167850

(ix) If a number has either 4 or 6 as its unit digit, then its square ends with 6.

Since 12796 has 6 as its unit digit, 6 will be the unit digit of its square. (6 × 6 = 36)

(x) If a number has 5 as its unit digit, then its square ends with 5.

Since 55555 has 5 as its unit digit, 5 will be the unit digit of its square. (5 × 5 = 25)

Similar Examples - 105, 85, 3425

**☛ Check: **NCERT Solutions for Class 8 Maths Chapter 6

**Video Solution:**

## 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

NCERT Solutions for Class 8 Maths Chapter 6 Exercise 6.1 Question 1

**Summary:**

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 will be (i) 1, (ii) 4, (iii) 1, (iv) 9, (v) 6, (vi) 9, (vii) 4, (viii) 0, (ix) 6, (x) 5

**☛ Related Questions:**

- The following numbers are obviously not perfect squares. Give reason. (i) 1057 (ii) 23453 (iii) 7928 (iv) 222222 (v) 64000 (vi) 89722 (vii) 222000 (viii) 505050
- The squares of which of the following would be odd numbers? (i) 431 (ii) 2826 (iii) 7779 (iv) 82004
- Observe the following pattern and find the missing digits. 112 = 121 1012 = 10201 10012 = 1002001 1000012 = 1....2....1 100000012 = ...........
- Observe the following pattern and supply the missing numbers. 112 = 121 1012 = 10201 101012 = 102030201 10101012 = ? ?2 = 10203040504030201

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