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 128 must be multiplied to get a perfect square?
- 2.What is 69²? =
- 3.What is the smallest whole number by which 44 must be multiplied to get a perfect square?
- 4.How many whole numbers lie between 39² and 40²?
- 5.What is 55²? =
- 6.What is the sum of the first 29 odd numbers (1 + 3 + 5 + …)?
- 7.How many whole numbers lie between 30² and 31²?
- 8.What is 59²? =
- 9.Which of these is a perfect square? (a) 854 (b) 841 (c) 897
- 10.What is the smallest whole number by which 98 must be divided to get a perfect square?
- 11.What is the smallest whole number by which 52 must be divided to get a perfect square?
- 12.What is the sum of the first 22 odd numbers (1 + 3 + 5 + …)?
- 13.How many whole numbers lie between 9² and 10²?
- 14.What is √784? =
- 15.A square garden has an area of 1024 square m. How long is each side (in m)?
- 16.What is 57²? =
- 17.What is √6241? =
- 18.A square garden has an area of 2704 square m. How long is each side (in m)?
- 19.What is the smallest whole number by which 490 must be multiplied to get a perfect square?
- 20.What is √5476? =
- 21.What is the smallest whole number by which 375 must be multiplied to get a perfect square?
- 22.What is √9801? =
- 23.What is 35²? =
- 24.What is the sum of the first 7 odd numbers (1 + 3 + 5 + …)?
- 25.What is the smallest whole number by which 52 must be multiplied to get a perfect square?
- 26.What is 19²? =
- 27.What is 53²? =
- 28.What is 26²? =
- 29.What is the sum of the first 30 odd numbers (1 + 3 + 5 + …)?
- 30.What is the sum of the first 11 odd numbers (1 + 3 + 5 + …)?
- 31.What is the sum of the first 8 odd numbers (1 + 3 + 5 + …)?
- 32.A square garden has an area of 1225 square m. How long is each side (in m)?
- 33.What is 73²? =
- 34.What is 93²? =
- 35.Which of these is a perfect square? (a) 749 (b) 729 (c) 748
- 36.What is 95²? =
- 37.What is 23²? =
- 38.What is 62²? =
- 39.A square garden has an area of 36 square m. How long is each side (in m)?
- 40.What is √1089? =
Answer key
- 2
- 4761
- 11
- 78
- 3025
- 841
- 60
- 3481
- 841
- 2
- 13
- 484
- 18
- 28
- 32
- 3249
- 79
- 52
- 10
- 74
- 15
- 99
- 1225
- 49
- 13
- 361
- 2809
- 676
- 900
- 121
- 64
- 35
- 5329
- 8649
- 729
- 9025
- 529
- 3844
- 6
- 33
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