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 81²? =
- 2.What is the sum of the first 15 odd numbers (1 + 3 + 5 + …)?
- 3.What is 18²? =
- 4.A square garden has an area of 529 square m. How long is each side (in m)?
- 5.What is 31²? =
- 6.A square garden has an area of 2601 square m. How long is each side (in m)?
- 7.What is the sum of the first 10 odd numbers (1 + 3 + 5 + …)?
- 8.What is 59²? =
- 9.What is 54²? =
- 10.A square garden has an area of 1024 square m. How long is each side (in m)?
- 11.What is 35²? =
- 12.What is 88²? =
- 13.What is 38²? =
- 14.What is √1936? =
- 15.Which of these is a perfect square? (a) 463 (b) 441 (c) 443
- 16.What is √6889? =
- 17.Which of these is a perfect square? (a) 145 (b) 144 (c) 158
- 18.What is the smallest whole number by which 54 must be divided to get a perfect square?
- 19.What is the sum of the first 14 odd numbers (1 + 3 + 5 + …)?
- 20.What is the sum of the first 29 odd numbers (1 + 3 + 5 + …)?
- 21.What is √8464? =
- 22.Which of these is a perfect square? (a) 196 (b) 220 (c) 198
- 23.A square garden has an area of 2116 square m. How long is each side (in m)?
- 24.What is 43²? =
- 25.What is the smallest whole number by which 294 must be multiplied to get a perfect square?
- 26.How many whole numbers lie between 20² and 21²?
- 27.What is the smallest whole number by which 243 must be multiplied to get a perfect square?
- 28.What is √2601? =
- 29.Which of these is a perfect square? (a) 120 (b) 107 (c) 100
- 30.A square garden has an area of 169 square m. How long is each side (in m)?
- 31.How many whole numbers lie between 21² and 22²?
- 32.How many whole numbers lie between 35² and 36²?
- 33.What is √5776? =
- 34.What is √9409? =
- 35.What is the smallest whole number by which 63 must be multiplied to get a perfect square?
- 36.What is the sum of the first 12 odd numbers (1 + 3 + 5 + …)?
- 37.What is √2209? =
- 38.What is the smallest whole number by which 24 must be divided to get a perfect square?
- 39.What is √1600? =
- 40.What is the sum of the first 23 odd numbers (1 + 3 + 5 + …)?
Answer key
- 6561
- 225
- 324
- 23
- 961
- 51
- 100
- 3481
- 2916
- 32
- 1225
- 7744
- 1444
- 44
- 441
- 83
- 144
- 6
- 196
- 841
- 92
- 196
- 46
- 1849
- 6
- 40
- 3
- 51
- 100
- 13
- 42
- 70
- 76
- 97
- 7
- 144
- 47
- 6
- 40
- 529
Free maths worksheets lessons, practice and worksheets at talentjr.in/maths-worksheets