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.A square garden has an area of 484 square m. How long is each side (in m)?
- 2.What is the smallest whole number by which 175 must be multiplied to get a perfect square?
- 3.What is the smallest whole number by which 56 must be multiplied to get a perfect square?
- 4.What is the smallest whole number by which 20 must be divided to get a perfect square?
- 5.What is 97²? =
- 6.How many whole numbers lie between 6² and 7²?
- 7.What is 68²? =
- 8.What is the sum of the first 12 odd numbers (1 + 3 + 5 + …)?
- 9.How many whole numbers lie between 8² and 9²?
- 10.What is the smallest whole number by which 294 must be multiplied to get a perfect square?
- 11.What is 77²? =
- 12.How many whole numbers lie between 18² and 19²?
- 13.What is √2916? =
- 14.What is 47²? =
- 15.What is 94²? =
- 16.A square garden has an area of 36 square m. How long is each side (in m)?
- 17.What is √169? =
- 18.What is √6724? =
- 19.A square garden has an area of 1681 square m. How long is each side (in m)?
- 20.How many whole numbers lie between 29² and 30²?
- 21.How many whole numbers lie between 48² and 49²?
- 22.What is the smallest whole number by which 539 must be divided to get a perfect square?
- 23.What is the sum of the first 10 odd numbers (1 + 3 + 5 + …)?
- 24.What is the sum of the first 21 odd numbers (1 + 3 + 5 + …)?
- 25.What is the smallest whole number by which 56 must be divided to get a perfect square?
- 26.Which of these is a perfect square? (a) 441 (b) 453 (c) 469
- 27.How many whole numbers lie between 16² and 17²?
- 28.What is 25²? =
- 29.What is √484? =
- 30.What is the smallest whole number by which 350 must be multiplied to get a perfect square?
- 31.How many whole numbers lie between 12² and 13²?
- 32.What is 41²? =
- 33.How many whole numbers lie between 37² and 38²?
- 34.What is √361? =
- 35.What is 81²? =
- 36.What is 14²? =
- 37.What is √1849? =
- 38.How many whole numbers lie between 39² and 40²?
- 39.What is the sum of the first 9 odd numbers (1 + 3 + 5 + …)?
- 40.How many whole numbers lie between 36² and 37²?
Answer key
- 22
- 7
- 14
- 5
- 9409
- 12
- 4624
- 144
- 16
- 6
- 5929
- 36
- 54
- 2209
- 8836
- 6
- 13
- 82
- 41
- 58
- 96
- 11
- 100
- 441
- 14
- 441
- 32
- 625
- 22
- 14
- 24
- 1681
- 74
- 19
- 6561
- 196
- 43
- 78
- 81
- 72
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