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 49²? =
- 2.What is the smallest whole number by which 128 must be multiplied to get a perfect square?
- 3.What is the sum of the first 9 odd numbers (1 + 3 + 5 + …)?
- 4.How many whole numbers lie between 33² and 34²?
- 5.What is the sum of the first 29 odd numbers (1 + 3 + 5 + …)?
- 6.What is 24²? =
- 7.What is 58²? =
- 8.What is 25²? =
- 9.How many whole numbers lie between 7² and 8²?
- 10.What is 91²? =
- 11.How many whole numbers lie between 38² and 39²?
- 12.How many whole numbers lie between 19² and 20²?
- 13.Which of these is a perfect square? (a) 1354 (b) 1316 (c) 1296
- 14.Which of these is a perfect square? (a) 565 (b) 534 (c) 529
- 15.What is the sum of the first 27 odd numbers (1 + 3 + 5 + …)?
- 16.Which of these is a perfect square? (a) 634 (b) 625 (c) 671
- 17.How many whole numbers lie between 25² and 26²?
- 18.What is √3600? =
- 19.How many whole numbers lie between 21² and 22²?
- 20.What is √2601? =
- 21.Which of these is a perfect square? (a) 1158 (b) 1156 (c) 1185
- 22.What is √841? =
- 23.What is 32²? =
- 24.What is √8100? =
- 25.What is the smallest whole number by which 396 must be divided to get a perfect square?
- 26.A square garden has an area of 2401 square m. How long is each side (in m)?
- 27.A square garden has an area of 196 square m. How long is each side (in m)?
- 28.What is 74²? =
- 29.A square garden has an area of 1681 square m. How long is each side (in m)?
- 30.What is √3249? =
- 31.A square garden has an area of 784 square m. How long is each side (in m)?
- 32.What is √529? =
- 33.How many whole numbers lie between 28² and 29²?
- 34.A square garden has an area of 81 square m. How long is each side (in m)?
- 35.What is the smallest whole number by which 540 must be multiplied to get a perfect square?
- 36.How many whole numbers lie between 41² and 42²?
- 37.A square garden has an area of 441 square m. How long is each side (in m)?
- 38.What is the smallest whole number by which 135 must be multiplied to get a perfect square?
- 39.What is the sum of the first 25 odd numbers (1 + 3 + 5 + …)?
- 40.What is √121? =
Answer key
- 2401
- 2
- 81
- 66
- 841
- 576
- 3364
- 625
- 14
- 8281
- 76
- 38
- 1296
- 529
- 729
- 625
- 50
- 60
- 42
- 51
- 1156
- 29
- 1024
- 90
- 11
- 49
- 14
- 5476
- 41
- 57
- 28
- 23
- 56
- 9
- 15
- 82
- 21
- 15
- 625
- 11
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