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 325 must be divided to get a perfect square?
- 2.What is the sum of the first 23 odd numbers (1 + 3 + 5 + …)?
- 3.What is 71²? =
- 4.What is √144? =
- 5.A square garden has an area of 2025 square m. How long is each side (in m)?
- 6.Which of these is a perfect square? (a) 447 (b) 444 (c) 441
- 7.How many whole numbers lie between 11² and 12²?
- 8.Which of these is a perfect square? (a) 689 (b) 682 (c) 676
- 9.Which of these is a perfect square? (a) 740 (b) 754 (c) 729
- 10.What is √3481? =
- 11.Which of these is a perfect square? (a) 1494 (b) 1457 (c) 1444
- 12.What is the sum of the first 22 odd numbers (1 + 3 + 5 + …)?
- 13.A square garden has an area of 169 square m. How long is each side (in m)?
- 14.What is the smallest whole number by which 1215 must be multiplied to get a perfect square?
- 15.What is 36²? =
- 16.What is the smallest whole number by which 50 must be multiplied to get a perfect square?
- 17.Which of these is a perfect square? (a) 1440 (b) 1431 (c) 1369
- 18.What is 86²? =
- 19.What is √2209? =
- 20.What is the sum of the first 8 odd numbers (1 + 3 + 5 + …)?
- 21.What is the sum of the first 28 odd numbers (1 + 3 + 5 + …)?
- 22.How many whole numbers lie between 46² and 47²?
- 23.A square garden has an area of 529 square m. How long is each side (in m)?
- 24.What is the sum of the first 27 odd numbers (1 + 3 + 5 + …)?
- 25.A square garden has an area of 3600 square m. How long is each side (in m)?
- 26.What is √2916? =
- 27.What is the sum of the first 26 odd numbers (1 + 3 + 5 + …)?
- 28.What is √2704? =
- 29.What is √7396? =
- 30.Which of these is a perfect square? (a) 400 (b) 414 (c) 433
- 31.How many whole numbers lie between 40² and 41²?
- 32.What is √5184? =
- 33.What is √7744? =
- 34.What is the smallest whole number by which 405 must be multiplied to get a perfect square?
- 35.What is √9409? =
- 36.What is 75²? =
- 37.A square garden has an area of 256 square m. How long is each side (in m)?
- 38.How many whole numbers lie between 42² and 43²?
- 39.What is the smallest whole number by which 98 must be multiplied to get a perfect square?
- 40.What is 13²? =
Answer key
- 13
- 529
- 5041
- 12
- 45
- 441
- 22
- 676
- 729
- 59
- 1444
- 484
- 13
- 15
- 1296
- 2
- 1369
- 7396
- 47
- 64
- 784
- 92
- 23
- 729
- 60
- 54
- 676
- 52
- 86
- 400
- 80
- 72
- 88
- 5
- 97
- 5625
- 16
- 84
- 2
- 169
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