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 18 must be multiplied to get a perfect square?
- 2.Which of these is a perfect square? (a) 361 (b) 371 (c) 380
- 3.A square garden has an area of 196 square m. How long is each side (in m)?
- 4.How many whole numbers lie between 17² and 18²?
- 5.What is 85²? =
- 6.What is the sum of the first 21 odd numbers (1 + 3 + 5 + …)?
- 7.What is √6889? =
- 8.What is √484? =
- 9.A square garden has an area of 361 square m. How long is each side (in m)?
- 10.What is 45²? =
- 11.Which of these is a perfect square? (a) 198 (b) 196 (c) 212
- 12.How many whole numbers lie between 9² and 10²?
- 13.What is √8649? =
- 14.What is 89²? =
- 15.What is 31²? =
- 16.What is the smallest whole number by which 75 must be divided to get a perfect square?
- 17.What is the sum of the first 14 odd numbers (1 + 3 + 5 + …)?
- 18.What is 70²? =
- 19.What is 82²? =
- 20.What is √625? =
- 21.Which of these is a perfect square? (a) 792 (b) 784 (c) 795
- 22.What is the sum of the first 17 odd numbers (1 + 3 + 5 + …)?
- 23.What is √784? =
- 24.Which of these is a perfect square? (a) 676 (b) 684 (c) 690
- 25.What is the smallest whole number by which 175 must be multiplied to get a perfect square?
- 26.What is the smallest whole number by which 18 must be divided to get a perfect square?
- 27.A square garden has an area of 1444 square m. How long is each side (in m)?
- 28.What is 33²? =
- 29.Which of these is a perfect square? (a) 266 (b) 261 (c) 256
- 30.How many whole numbers lie between 19² and 20²?
- 31.A square garden has an area of 1849 square m. How long is each side (in m)?
- 32.What is the smallest whole number by which 896 must be multiplied to get a perfect square?
- 33.What is √144? =
- 34.What is the smallest whole number by which 180 must be divided to get a perfect square?
- 35.What is √3844? =
- 36.How many whole numbers lie between 34² and 35²?
- 37.How many whole numbers lie between 16² and 17²?
- 38.How many whole numbers lie between 11² and 12²?
- 39.What is √8100? =
- 40.Which of these is a perfect square? (a) 1089 (b) 1106 (c) 1121
Answer key
- 2
- 361
- 14
- 34
- 7225
- 441
- 83
- 22
- 19
- 2025
- 196
- 18
- 93
- 7921
- 961
- 3
- 196
- 4900
- 6724
- 25
- 784
- 289
- 28
- 676
- 7
- 2
- 38
- 1089
- 256
- 38
- 43
- 14
- 12
- 5
- 62
- 68
- 32
- 22
- 90
- 1089
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