Class 8 Maths Worksheet: Squares and Square Roots
The method (Pairs make squares): Square: n × n. Quick way: (a + b)² = a² + 2ab + b², e.g. 42² = 1600 + 160 + 4. Square root: the number that times itself gives the square; a square ending in 4 has a root ending in 2 or 8. Make a perfect square: break into primes; multiply (or divide) by the prime left without a partner. 1 + 3 + 5 + … (n odd numbers) = n². Between n² and (n + 1)² there are 2n whole numbers.
NameDateTime takenScore ___ / 40
- 1.What is the smallest whole number by which 40 must be divided to get a perfect square?
- 2.What is the sum of the first 8 odd numbers (1 + 3 + 5 + …)?
- 3.How many whole numbers lie between 48² and 49²?
- 4.What is √1444? =
- 5.What is √6724? =
- 6.How many whole numbers lie between 13² and 14²?
- 7.What is √2704? =
- 8.What is the smallest whole number by which 704 must be multiplied to get a perfect square?
- 9.A square garden has an area of 3364 square m. How long is each side (in m)?
- 10.What is 27²? =
- 11.What is 12²? =
- 12.Which of these is a perfect square? (a) 1600 (b) 1618 (c) 1648
- 13.What is the sum of the first 9 odd numbers (1 + 3 + 5 + …)?
- 14.Which of these is a perfect square? (a) 120 (b) 107 (c) 100
- 15.What is √5476? =
- 16.What is √1156? =
- 17.What is 61²? =
- 18.What is the sum of the first 29 odd numbers (1 + 3 + 5 + …)?
- 19.Which of these is a perfect square? (a) 443 (b) 454 (c) 441
- 20.What is √1936? =
- 21.What is 93²? =
- 22.How many whole numbers lie between 49² and 50²?
- 23.A square garden has an area of 441 square m. How long is each side (in m)?
- 24.Which of these is a perfect square? (a) 192 (b) 185 (c) 169
- 25.How many whole numbers lie between 12² and 13²?
- 26.What is 95²? =
- 27.What is 47²? =
- 28.What is √1764? =
- 29.How many whole numbers lie between 20² and 21²?
- 30.How many whole numbers lie between 41² and 42²?
- 31.What is 51²? =
- 32.How many whole numbers lie between 37² and 38²?
- 33.What is the smallest whole number by which 245 must be divided to get a perfect square?
- 34.What is the smallest whole number by which 686 must be divided to get a perfect square?
- 35.What is the sum of the first 23 odd numbers (1 + 3 + 5 + …)?
- 36.A square garden has an area of 2304 square m. How long is each side (in m)?
- 37.What is the smallest whole number by which 45 must be multiplied to get a perfect square?
- 38.Which of these is a perfect square? (a) 144 (b) 156 (c) 145
- 39.Which of these is a perfect square? (a) 386 (b) 361 (c) 381
- 40.What is √900? =
Answer key
- 10
- 64
- 96
- 38
- 82
- 26
- 52
- 11
- 58
- 729
- 144
- 1600
- 81
- 100
- 74
- 34
- 3721
- 841
- 441
- 44
- 8649
- 98
- 21
- 169
- 24
- 9025
- 2209
- 42
- 40
- 82
- 2601
- 74
- 5
- 14
- 529
- 48
- 5
- 144
- 361
- 30
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