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 sum of the first 25 odd numbers (1 + 3 + 5 + …)?
- 2.What is √6241? =
- 3.How many whole numbers lie between 15² and 16²?
- 4.Which of these is a perfect square? (a) 219 (b) 196 (c) 207
- 5.A square garden has an area of 3136 square m. How long is each side (in m)?
- 6.What is the smallest whole number by which 98 must be multiplied to get a perfect square?
- 7.What is 31²? =
- 8.What is √961? =
- 9.What is 94²? =
- 10.What is the smallest whole number by which 90 must be multiplied to get a perfect square?
- 11.How many whole numbers lie between 32² and 33²?
- 12.What is √3136? =
- 13.A square garden has an area of 1156 square m. How long is each side (in m)?
- 14.Which of these is a perfect square? (a) 727 (b) 676 (c) 682
- 15.A square garden has an area of 1764 square m. How long is each side (in m)?
- 16.What is the smallest whole number by which 180 must be divided to get a perfect square?
- 17.Which of these is a perfect square? (a) 385 (b) 391 (c) 361
- 18.What is 65²? =
- 19.What is the sum of the first 16 odd numbers (1 + 3 + 5 + …)?
- 20.Which of these is a perfect square? (a) 513 (b) 516 (c) 484
- 21.What is √289? =
- 22.A square garden has an area of 1296 square m. How long is each side (in m)?
- 23.How many whole numbers lie between 35² and 36²?
- 24.What is 96²? =
- 25.How many whole numbers lie between 20² and 21²?
- 26.A square garden has an area of 3600 square m. How long is each side (in m)?
- 27.How many whole numbers lie between 34² and 35²?
- 28.What is √8100? =
- 29.What is 76²? =
- 30.A square garden has an area of 3364 square m. How long is each side (in m)?
- 31.What is the smallest whole number by which 567 must be multiplied to get a perfect square?
- 32.Which of these is a perfect square? (a) 1243 (b) 1225 (c) 1229
- 33.A square garden has an area of 225 square m. How long is each side (in m)?
- 34.Which of these is a perfect square? (a) 1089 (b) 1152 (c) 1144
- 35.Which of these is a perfect square? (a) 1507 (b) 1444 (c) 1474
- 36.What is 39²? =
- 37.What is the sum of the first 15 odd numbers (1 + 3 + 5 + …)?
- 38.How many whole numbers lie between 39² and 40²?
- 39.What is 92²? =
- 40.How many whole numbers lie between 27² and 28²?
Answer key
- 625
- 79
- 30
- 196
- 56
- 2
- 961
- 31
- 8836
- 10
- 64
- 56
- 34
- 676
- 42
- 5
- 361
- 4225
- 256
- 484
- 17
- 36
- 70
- 9216
- 40
- 60
- 68
- 90
- 5776
- 58
- 7
- 1225
- 15
- 1089
- 1444
- 1521
- 225
- 78
- 8464
- 54
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