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 24 odd numbers (1 + 3 + 5 + …)?
- 2.How many whole numbers lie between 48² and 49²?
- 3.What is the smallest whole number by which 44 must be divided to get a perfect square?
- 4.What is the smallest whole number by which 192 must be multiplied to get a perfect square?
- 5.What is the smallest whole number by which 150 must be divided to get a perfect square?
- 6.What is 27²? =
- 7.What is the sum of the first 18 odd numbers (1 + 3 + 5 + …)?
- 8.A square garden has an area of 441 square m. How long is each side (in m)?
- 9.What is √2601? =
- 10.What is the smallest whole number by which 8 must be multiplied to get a perfect square?
- 11.A square garden has an area of 1156 square m. How long is each side (in m)?
- 12.A square garden has an area of 676 square m. How long is each side (in m)?
- 13.A square garden has an area of 1024 square m. How long is each side (in m)?
- 14.What is the sum of the first 20 odd numbers (1 + 3 + 5 + …)?
- 15.What is the sum of the first 28 odd numbers (1 + 3 + 5 + …)?
- 16.What is the smallest whole number by which 704 must be multiplied to get a perfect square?
- 17.Which of these is a perfect square? (a) 1515 (b) 1444 (c) 1472
- 18.What is 75²? =
- 19.What is √1089? =
- 20.What is 99²? =
- 21.Which of these is a perfect square? (a) 865 (b) 841 (c) 861
- 22.What is √7225? =
- 23.What is the smallest whole number by which 448 must be multiplied to get a perfect square?
- 24.What is 80²? =
- 25.What is √4225? =
- 26.A square garden has an area of 81 square m. How long is each side (in m)?
- 27.What is √9216? =
- 28.How many whole numbers lie between 9² and 10²?
- 29.What is 11²? =
- 30.What is 31²? =
- 31.What is 32²? =
- 32.What is 49²? =
- 33.What is the sum of the first 25 odd numbers (1 + 3 + 5 + …)?
- 34.A square garden has an area of 2401 square m. How long is each side (in m)?
- 35.Which of these is a perfect square? (a) 196 (b) 214 (c) 202
- 36.What is 14²? =
- 37.What is the smallest whole number by which 128 must be divided to get a perfect square?
- 38.What is √484? =
- 39.Which of these is a perfect square? (a) 324 (b) 349 (c) 359
- 40.Which of these is a perfect square? (a) 833 (b) 784 (c) 832
Answer key
- 576
- 96
- 11
- 3
- 6
- 729
- 324
- 21
- 51
- 2
- 34
- 26
- 32
- 400
- 784
- 11
- 1444
- 5625
- 33
- 9801
- 841
- 85
- 7
- 6400
- 65
- 9
- 96
- 18
- 121
- 961
- 1024
- 2401
- 625
- 49
- 196
- 196
- 2
- 22
- 324
- 784
Free maths worksheets lessons, practice and worksheets at talentjr.in/maths-worksheets