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 √1600? =
- 2.What is √5625? =
- 3.What is the sum of the first 9 odd numbers (1 + 3 + 5 + …)?
- 4.What is the sum of the first 27 odd numbers (1 + 3 + 5 + …)?
- 5.What is 63²? =
- 6.What is the sum of the first 15 odd numbers (1 + 3 + 5 + …)?
- 7.How many whole numbers lie between 45² and 46²?
- 8.What is √1849? =
- 9.How many whole numbers lie between 17² and 18²?
- 10.What is 47²? =
- 11.What is the sum of the first 5 odd numbers (1 + 3 + 5 + …)?
- 12.What is the smallest whole number by which 245 must be multiplied to get a perfect square?
- 13.How many whole numbers lie between 10² and 11²?
- 14.A square garden has an area of 36 square m. How long is each side (in m)?
- 15.What is the smallest whole number by which 44 must be divided to get a perfect square?
- 16.A square garden has an area of 3600 square m. How long is each side (in m)?
- 17.How many whole numbers lie between 5² and 6²?
- 18.What is the sum of the first 11 odd numbers (1 + 3 + 5 + …)?
- 19.What is 76²? =
- 20.What is 26²? =
- 21.What is the smallest whole number by which 8 must be multiplied to get a perfect square?
- 22.What is √1225? =
- 23.A square garden has an area of 2401 square m. How long is each side (in m)?
- 24.What is 99²? =
- 25.How many whole numbers lie between 29² and 30²?
- 26.Which of these is a perfect square? (a) 904 (b) 900 (c) 921
- 27.How many whole numbers lie between 25² and 26²?
- 28.What is 38²? =
- 29.What is √6400? =
- 30.A square garden has an area of 2116 square m. How long is each side (in m)?
- 31.What is the smallest whole number by which 1053 must be divided to get a perfect square?
- 32.What is 11²? =
- 33.What is the sum of the first 23 odd numbers (1 + 3 + 5 + …)?
- 34.What is the sum of the first 16 odd numbers (1 + 3 + 5 + …)?
- 35.A square garden has an area of 2809 square m. How long is each side (in m)?
- 36.Which of these is a perfect square? (a) 106 (b) 100 (c) 107
- 37.How many whole numbers lie between 7² and 8²?
- 38.A square garden has an area of 1089 square m. How long is each side (in m)?
- 39.How many whole numbers lie between 43² and 44²?
- 40.What is the sum of the first 6 odd numbers (1 + 3 + 5 + …)?
Answer key
- 40
- 75
- 81
- 729
- 3969
- 225
- 90
- 43
- 34
- 2209
- 25
- 5
- 20
- 6
- 11
- 60
- 10
- 121
- 5776
- 676
- 2
- 35
- 49
- 9801
- 58
- 900
- 50
- 1444
- 80
- 46
- 13
- 121
- 529
- 256
- 53
- 100
- 14
- 33
- 86
- 36
Free maths worksheets lessons, practice and worksheets at talentjr.in/maths-worksheets