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 70²? =
- 2.What is the smallest whole number by which 320 must be multiplied to get a perfect square?
- 3.A square garden has an area of 256 square m. How long is each side (in m)?
- 4.How many whole numbers lie between 6² and 7²?
- 5.What is the smallest whole number by which 75 must be multiplied to get a perfect square?
- 6.What is 39²? =
- 7.What is 89²? =
- 8.What is √2500? =
- 9.What is 42²? =
- 10.Which of these is a perfect square? (a) 1641 (b) 1600 (c) 1619
- 11.What is √324? =
- 12.What is √9216? =
- 13.What is the sum of the first 6 odd numbers (1 + 3 + 5 + …)?
- 14.What is 60²? =
- 15.What is the sum of the first 18 odd numbers (1 + 3 + 5 + …)?
- 16.A square garden has an area of 3364 square m. How long is each side (in m)?
- 17.What is the sum of the first 14 odd numbers (1 + 3 + 5 + …)?
- 18.How many whole numbers lie between 13² and 14²?
- 19.A square garden has an area of 196 square m. How long is each side (in m)?
- 20.What is 63²? =
- 21.What is √6084? =
- 22.What is 23²? =
- 23.What is the sum of the first 19 odd numbers (1 + 3 + 5 + …)?
- 24.What is 74²? =
- 25.How many whole numbers lie between 48² and 49²?
- 26.What is the smallest whole number by which 162 must be multiplied to get a perfect square?
- 27.Which of these is a perfect square? (a) 100 (b) 102 (c) 104
- 28.Which of these is a perfect square? (a) 221 (b) 205 (c) 196
- 29.A square garden has an area of 3481 square m. How long is each side (in m)?
- 30.What is the sum of the first 9 odd numbers (1 + 3 + 5 + …)?
- 31.What is the sum of the first 27 odd numbers (1 + 3 + 5 + …)?
- 32.Which of these is a perfect square? (a) 191 (b) 189 (c) 169
- 33.What is the smallest whole number by which 540 must be divided to get a perfect square?
- 34.What is √1681? =
- 35.How many whole numbers lie between 37² and 38²?
- 36.How many whole numbers lie between 18² and 19²?
- 37.What is the smallest whole number by which 126 must be multiplied to get a perfect square?
- 38.What is √7225? =
- 39.How many whole numbers lie between 41² and 42²?
- 40.A square garden has an area of 841 square m. How long is each side (in m)?
Answer key
- 4900
- 5
- 16
- 12
- 3
- 1521
- 7921
- 50
- 1764
- 1600
- 18
- 96
- 36
- 3600
- 324
- 58
- 196
- 26
- 14
- 3969
- 78
- 529
- 361
- 5476
- 96
- 2
- 100
- 196
- 59
- 81
- 729
- 169
- 15
- 41
- 74
- 36
- 14
- 85
- 82
- 29
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