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 11 odd numbers (1 + 3 + 5 + …)?
- 2.How many whole numbers lie between 22² and 23²?
- 3.How many whole numbers lie between 49² and 50²?
- 4.How many whole numbers lie between 47² and 48²?
- 5.What is √400? =
- 6.A square garden has an area of 529 square m. How long is each side (in m)?
- 7.How many whole numbers lie between 26² and 27²?
- 8.A square garden has an area of 3364 square m. How long is each side (in m)?
- 9.A square garden has an area of 25 square m. How long is each side (in m)?
- 10.A square garden has an area of 196 square m. How long is each side (in m)?
- 11.How many whole numbers lie between 34² and 35²?
- 12.What is √3721? =
- 13.What is 80²? =
- 14.What is the sum of the first 6 odd numbers (1 + 3 + 5 + …)?
- 15.What is 31²? =
- 16.What is 91²? =
- 17.A square garden has an area of 2025 square m. How long is each side (in m)?
- 18.Which of these is a perfect square? (a) 144 (b) 168 (c) 153
- 19.A square garden has an area of 1600 square m. How long is each side (in m)?
- 20.Which of these is a perfect square? (a) 225 (b) 250 (c) 241
- 21.How many whole numbers lie between 18² and 19²?
- 22.Which of these is a perfect square? (a) 441 (b) 448 (c) 479
- 23.What is the sum of the first 21 odd numbers (1 + 3 + 5 + …)?
- 24.What is 96²? =
- 25.What is the smallest whole number by which 250 must be multiplied to get a perfect square?
- 26.What is 93²? =
- 27.A square garden has an area of 100 square m. How long is each side (in m)?
- 28.A square garden has an area of 324 square m. How long is each side (in m)?
- 29.How many whole numbers lie between 8² and 9²?
- 30.How many whole numbers lie between 24² and 25²?
- 31.What is 75²? =
- 32.How many whole numbers lie between 14² and 15²?
- 33.What is √1024? =
- 34.What is the smallest whole number by which 175 must be divided to get a perfect square?
- 35.What is 22²? =
- 36.How many whole numbers lie between 11² and 12²?
- 37.What is the smallest whole number by which 18 must be multiplied to get a perfect square?
- 38.What is 99²? =
- 39.What is the sum of the first 28 odd numbers (1 + 3 + 5 + …)?
- 40.What is √225? =
Answer key
- 121
- 44
- 98
- 94
- 20
- 23
- 52
- 58
- 5
- 14
- 68
- 61
- 6400
- 36
- 961
- 8281
- 45
- 144
- 40
- 225
- 36
- 441
- 441
- 9216
- 10
- 8649
- 10
- 18
- 16
- 48
- 5625
- 28
- 32
- 7
- 484
- 22
- 2
- 9801
- 784
- 15
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