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 79²? =
- 2.Which of these is a perfect square? (a) 400 (b) 424 (c) 415
- 3.What is the sum of the first 9 odd numbers (1 + 3 + 5 + …)?
- 4.What is the smallest whole number by which 704 must be multiplied to get a perfect square?
- 5.A square garden has an area of 1600 square m. How long is each side (in m)?
- 6.What is 55²? =
- 7.A square garden has an area of 576 square m. How long is each side (in m)?
- 8.How many whole numbers lie between 50² and 51²?
- 9.What is √3844? =
- 10.A square garden has an area of 2304 square m. How long is each side (in m)?
- 11.What is √256? =
- 12.What is the sum of the first 5 odd numbers (1 + 3 + 5 + …)?
- 13.Which of these is a perfect square? (a) 495 (b) 509 (c) 484
- 14.What is the smallest whole number by which 384 must be divided to get a perfect square?
- 15.What is √3481? =
- 16.What is √576? =
- 17.What is the smallest whole number by which 128 must be divided to get a perfect square?
- 18.Which of these is a perfect square? (a) 736 (b) 729 (c) 749
- 19.Which of these is a perfect square? (a) 566 (b) 543 (c) 529
- 20.What is the sum of the first 23 odd numbers (1 + 3 + 5 + …)?
- 21.A square garden has an area of 144 square m. How long is each side (in m)?
- 22.What is 71²? =
- 23.Which of these is a perfect square? (a) 1129 (b) 1151 (c) 1089
- 24.A square garden has an area of 256 square m. How long is each side (in m)?
- 25.What is the sum of the first 6 odd numbers (1 + 3 + 5 + …)?
- 26.What is 28²? =
- 27.What is the smallest whole number by which 8 must be divided to get a perfect square?
- 28.What is the smallest whole number by which 108 must be divided to get a perfect square?
- 29.What is the sum of the first 12 odd numbers (1 + 3 + 5 + …)?
- 30.Which of these is a perfect square? (a) 873 (b) 841 (c) 867
- 31.What is 16²? =
- 32.What is 89²? =
- 33.What is √900? =
- 34.What is 48²? =
- 35.What is the sum of the first 24 odd numbers (1 + 3 + 5 + …)?
- 36.What is the smallest whole number by which 350 must be divided to get a perfect square?
- 37.How many whole numbers lie between 13² and 14²?
- 38.What is √9409? =
- 39.Which of these is a perfect square? (a) 256 (b) 263 (c) 259
- 40.What is √729? =
Answer key
- 6241
- 400
- 81
- 11
- 40
- 3025
- 24
- 100
- 62
- 48
- 16
- 25
- 484
- 6
- 59
- 24
- 2
- 729
- 529
- 529
- 12
- 5041
- 1089
- 16
- 36
- 784
- 2
- 3
- 144
- 841
- 256
- 7921
- 30
- 2304
- 576
- 14
- 26
- 97
- 256
- 27
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