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 6 odd numbers (1 + 3 + 5 + …)?
- 2.What is √1369? =
- 3.What is the smallest whole number by which 72 must be divided to get a perfect square?
- 4.What is the sum of the first 17 odd numbers (1 + 3 + 5 + …)?
- 5.What is 45²? =
- 6.What is 28²? =
- 7.What is the sum of the first 27 odd numbers (1 + 3 + 5 + …)?
- 8.What is 41²? =
- 9.Which of these is a perfect square? (a) 1444 (b) 1480 (c) 1496
- 10.What is 55²? =
- 11.What is the smallest whole number by which 224 must be multiplied to get a perfect square?
- 12.What is the sum of the first 10 odd numbers (1 + 3 + 5 + …)?
- 13.How many whole numbers lie between 49² and 50²?
- 14.What is the sum of the first 25 odd numbers (1 + 3 + 5 + …)?
- 15.What is 22²? =
- 16.What is 24²? =
- 17.What is 67²? =
- 18.A square garden has an area of 2916 square m. How long is each side (in m)?
- 19.What is the smallest whole number by which 90 must be divided to get a perfect square?
- 20.How many whole numbers lie between 34² and 35²?
- 21.What is √5776? =
- 22.A square garden has an area of 1600 square m. How long is each side (in m)?
- 23.How many whole numbers lie between 23² and 24²?
- 24.What is √8464? =
- 25.What is 51²? =
- 26.How many whole numbers lie between 21² and 22²?
- 27.What is 79²? =
- 28.How many whole numbers lie between 10² and 11²?
- 29.What is 29²? =
- 30.A square garden has an area of 1764 square m. How long is each side (in m)?
- 31.What is the sum of the first 29 odd numbers (1 + 3 + 5 + …)?
- 32.Which of these is a perfect square? (a) 841 (b) 875 (c) 896
- 33.What is the smallest whole number by which 128 must be divided to get a perfect square?
- 34.What is √784? =
- 35.A square garden has an area of 729 square m. How long is each side (in m)?
- 36.Which of these is a perfect square? (a) 1427 (b) 1369 (c) 1387
- 37.What is √9025? =
- 38.What is the sum of the first 30 odd numbers (1 + 3 + 5 + …)?
- 39.What is √6889? =
- 40.How many whole numbers lie between 45² and 46²?
Answer key
- 36
- 37
- 2
- 289
- 2025
- 784
- 729
- 1681
- 1444
- 3025
- 14
- 100
- 98
- 625
- 484
- 576
- 4489
- 54
- 10
- 68
- 76
- 40
- 46
- 92
- 2601
- 42
- 6241
- 20
- 841
- 42
- 841
- 841
- 2
- 28
- 27
- 1369
- 95
- 900
- 83
- 90
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