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 √8649? =
- 2.What is the smallest whole number by which 28 must be multiplied to get a perfect square?
- 3.What is the sum of the first 19 odd numbers (1 + 3 + 5 + …)?
- 4.What is 44²? =
- 5.What is √400? =
- 6.What is 13²? =
- 7.Which of these is a perfect square? (a) 900 (b) 952 (c) 908
- 8.What is the smallest whole number by which 48 must be multiplied to get a perfect square?
- 9.What is 45²? =
- 10.How many whole numbers lie between 49² and 50²?
- 11.What is the sum of the first 26 odd numbers (1 + 3 + 5 + …)?
- 12.What is the sum of the first 12 odd numbers (1 + 3 + 5 + …)?
- 13.What is the smallest whole number by which 80 must be multiplied to get a perfect square?
- 14.How many whole numbers lie between 18² and 19²?
- 15.What is the smallest whole number by which 343 must be divided to get a perfect square?
- 16.Which of these is a perfect square? (a) 100 (b) 109 (c) 108
- 17.What is 48²? =
- 18.A square garden has an area of 3025 square m. How long is each side (in m)?
- 19.What is the smallest whole number by which 245 must be multiplied to get a perfect square?
- 20.A square garden has an area of 900 square m. How long is each side (in m)?
- 21.What is √121? =
- 22.What is 55²? =
- 23.What is the smallest whole number by which 325 must be divided to get a perfect square?
- 24.A square garden has an area of 36 square m. How long is each side (in m)?
- 25.What is √3364? =
- 26.How many whole numbers lie between 12² and 13²?
- 27.Which of these is a perfect square? (a) 529 (b) 532 (c) 558
- 28.What is 53²? =
- 29.How many whole numbers lie between 15² and 16²?
- 30.What is the sum of the first 6 odd numbers (1 + 3 + 5 + …)?
- 31.What is 15²? =
- 32.What is √2209? =
- 33.A square garden has an area of 169 square m. How long is each side (in m)?
- 34.What is the smallest whole number by which 240 must be divided to get a perfect square?
- 35.What is √324? =
- 36.Which of these is a perfect square? (a) 478 (b) 441 (c) 447
- 37.A square garden has an area of 64 square m. How long is each side (in m)?
- 38.What is 97²? =
- 39.How many whole numbers lie between 19² and 20²?
- 40.What is 93²? =
Answer key
- 93
- 7
- 361
- 1936
- 20
- 169
- 900
- 3
- 2025
- 98
- 676
- 144
- 5
- 36
- 7
- 100
- 2304
- 55
- 5
- 30
- 11
- 3025
- 13
- 6
- 58
- 24
- 529
- 2809
- 30
- 36
- 225
- 47
- 13
- 15
- 18
- 441
- 8
- 9409
- 38
- 8649
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