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 √6724? =
- 2.A square garden has an area of 2209 square m. How long is each side (in m)?
- 3.Which of these is a perfect square? (a) 1623 (b) 1625 (c) 1600
- 4.Which of these is a perfect square? (a) 389 (b) 366 (c) 361
- 5.What is √2704? =
- 6.How many whole numbers lie between 40² and 41²?
- 7.What is √9409? =
- 8.What is √4624? =
- 9.What is √7569? =
- 10.What is √3136? =
- 11.What is the sum of the first 20 odd numbers (1 + 3 + 5 + …)?
- 12.What is 37²? =
- 13.What is 31²? =
- 14.How many whole numbers lie between 49² and 50²?
- 15.What is 50²? =
- 16.What is 51²? =
- 17.Which of these is a perfect square? (a) 213 (b) 196 (c) 223
- 18.What is √900? =
- 19.What is √2500? =
- 20.What is 74²? =
- 21.Which of these is a perfect square? (a) 430 (b) 404 (c) 400
- 22.What is 49²? =
- 23.What is the sum of the first 8 odd numbers (1 + 3 + 5 + …)?
- 24.What is √8836? =
- 25.What is 43²? =
- 26.What is the smallest whole number by which 1215 must be divided to get a perfect square?
- 27.A square garden has an area of 64 square m. How long is each side (in m)?
- 28.What is 42²? =
- 29.A square garden has an area of 784 square m. How long is each side (in m)?
- 30.What is the sum of the first 10 odd numbers (1 + 3 + 5 + …)?
- 31.What is the smallest whole number by which 12 must be multiplied to get a perfect square?
- 32.What is 63²? =
- 33.A square garden has an area of 121 square m. How long is each side (in m)?
- 34.What is the sum of the first 30 odd numbers (1 + 3 + 5 + …)?
- 35.What is √9216? =
- 36.What is the sum of the first 7 odd numbers (1 + 3 + 5 + …)?
- 37.What is the smallest whole number by which 54 must be multiplied to get a perfect square?
- 38.What is the sum of the first 14 odd numbers (1 + 3 + 5 + …)?
- 39.What is the smallest whole number by which 891 must be multiplied to get a perfect square?
- 40.What is 40²? =
Answer key
- 82
- 47
- 1600
- 361
- 52
- 80
- 97
- 68
- 87
- 56
- 400
- 1369
- 961
- 98
- 2500
- 2601
- 196
- 30
- 50
- 5476
- 400
- 2401
- 64
- 94
- 1849
- 15
- 8
- 1764
- 28
- 100
- 3
- 3969
- 11
- 900
- 96
- 49
- 6
- 196
- 11
- 1600
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