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 5 odd numbers (1 + 3 + 5 + …)?
- 2.How many whole numbers lie between 33² and 34²?
- 3.Which of these is a perfect square? (a) 729 (b) 757 (c) 763
- 4.What is the smallest whole number by which 24 must be divided to get a perfect square?
- 5.What is the sum of the first 8 odd numbers (1 + 3 + 5 + …)?
- 6.What is the sum of the first 19 odd numbers (1 + 3 + 5 + …)?
- 7.A square garden has an area of 2601 square m. How long is each side (in m)?
- 8.What is the smallest whole number by which 405 must be divided to get a perfect square?
- 9.What is 33²? =
- 10.What is √4624? =
- 11.What is √529? =
- 12.How many whole numbers lie between 19² and 20²?
- 13.A square garden has an area of 3249 square m. How long is each side (in m)?
- 14.Which of these is a perfect square? (a) 1024 (b) 1081 (c) 1079
- 15.A square garden has an area of 2209 square m. How long is each side (in m)?
- 16.What is √1936? =
- 17.What is the smallest whole number by which 18 must be multiplied to get a perfect square?
- 18.Which of these is a perfect square? (a) 532 (b) 529 (c) 568
- 19.How many whole numbers lie between 34² and 35²?
- 20.What is 25²? =
- 21.What is the smallest whole number by which 448 must be multiplied to get a perfect square?
- 22.A square garden has an area of 49 square m. How long is each side (in m)?
- 23.What is the sum of the first 27 odd numbers (1 + 3 + 5 + …)?
- 24.Which of these is a perfect square? (a) 1296 (b) 1318 (c) 1321
- 25.What is 29²? =
- 26.What is the smallest whole number by which 12 must be divided to get a perfect square?
- 27.What is the smallest whole number by which 96 must be divided to get a perfect square?
- 28.How many whole numbers lie between 39² and 40²?
- 29.What is the sum of the first 18 odd numbers (1 + 3 + 5 + …)?
- 30.What is the smallest whole number by which 810 must be multiplied to get a perfect square?
- 31.Which of these is a perfect square? (a) 714 (b) 690 (c) 676
- 32.What is √6724? =
- 33.How many whole numbers lie between 12² and 13²?
- 34.Which of these is a perfect square? (a) 625 (b) 674 (c) 627
- 35.What is 62²? =
- 36.What is 22²? =
- 37.What is 21²? =
- 38.What is the sum of the first 21 odd numbers (1 + 3 + 5 + …)?
- 39.What is 92²? =
- 40.What is 89²? =
Answer key
- 25
- 66
- 729
- 6
- 64
- 361
- 51
- 5
- 1089
- 68
- 23
- 38
- 57
- 1024
- 47
- 44
- 2
- 529
- 68
- 625
- 7
- 7
- 729
- 1296
- 841
- 3
- 6
- 78
- 324
- 10
- 676
- 82
- 24
- 625
- 3844
- 484
- 441
- 441
- 8464
- 7921
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