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 12 must be divided to get a perfect square?
- 2.What is the sum of the first 20 odd numbers (1 + 3 + 5 + …)?
- 3.How many whole numbers lie between 28² and 29²?
- 4.How many whole numbers lie between 15² and 16²?
- 5.How many whole numbers lie between 22² and 23²?
- 6.What is √5329? =
- 7.What is 49²? =
- 8.What is 78²? =
- 9.What is the sum of the first 6 odd numbers (1 + 3 + 5 + …)?
- 10.How many whole numbers lie between 9² and 10²?
- 11.How many whole numbers lie between 50² and 51²?
- 12.What is √4225? =
- 13.A square garden has an area of 1369 square m. How long is each side (in m)?
- 14.What is the smallest whole number by which 56 must be divided to get a perfect square?
- 15.Which of these is a perfect square? (a) 144 (b) 161 (c) 168
- 16.A square garden has an area of 729 square m. How long is each side (in m)?
- 17.A square garden has an area of 3600 square m. How long is each side (in m)?
- 18.What is the sum of the first 9 odd numbers (1 + 3 + 5 + …)?
- 19.A square garden has an area of 25 square m. How long is each side (in m)?
- 20.What is the smallest whole number by which 99 must be multiplied to get a perfect square?
- 21.A square garden has an area of 289 square m. How long is each side (in m)?
- 22.What is √4096? =
- 23.What is the sum of the first 24 odd numbers (1 + 3 + 5 + …)?
- 24.What is the smallest whole number by which 704 must be multiplied to get a perfect square?
- 25.How many whole numbers lie between 7² and 8²?
- 26.What is the sum of the first 7 odd numbers (1 + 3 + 5 + …)?
- 27.What is √121? =
- 28.What is √3721? =
- 29.What is the sum of the first 23 odd numbers (1 + 3 + 5 + …)?
- 30.How many whole numbers lie between 24² and 25²?
- 31.How many whole numbers lie between 6² and 7²?
- 32.A square garden has an area of 81 square m. How long is each side (in m)?
- 33.What is the smallest whole number by which 50 must be divided to get a perfect square?
- 34.What is the sum of the first 26 odd numbers (1 + 3 + 5 + …)?
- 35.What is 26²? =
- 36.What is 14²? =
- 37.What is √1849? =
- 38.What is 35²? =
- 39.Which of these is a perfect square? (a) 576 (b) 608 (c) 593
- 40.What is 94²? =
Answer key
- 3
- 400
- 56
- 30
- 44
- 73
- 2401
- 6084
- 36
- 18
- 100
- 65
- 37
- 14
- 144
- 27
- 60
- 81
- 5
- 11
- 17
- 64
- 576
- 11
- 14
- 49
- 11
- 61
- 529
- 48
- 12
- 9
- 2
- 676
- 676
- 196
- 43
- 1225
- 576
- 8836
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