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.Which of these is a perfect square? (a) 194 (b) 193 (c) 169
- 2.What is the smallest whole number by which 448 must be divided to get a perfect square?
- 3.What is 94²? =
- 4.How many whole numbers lie between 20² and 21²?
- 5.What is √3844? =
- 6.Which of these is a perfect square? (a) 1527 (b) 1521 (c) 1523
- 7.Which of these is a perfect square? (a) 914 (b) 943 (c) 900
- 8.What is the smallest whole number by which 48 must be multiplied to get a perfect square?
- 9.A square garden has an area of 225 square m. How long is each side (in m)?
- 10.A square garden has an area of 3364 square m. How long is each side (in m)?
- 11.What is the sum of the first 11 odd numbers (1 + 3 + 5 + …)?
- 12.How many whole numbers lie between 30² and 31²?
- 13.What is the smallest whole number by which 180 must be divided to get a perfect square?
- 14.What is √144? =
- 15.A square garden has an area of 961 square m. How long is each side (in m)?
- 16.A square garden has an area of 3025 square m. How long is each side (in m)?
- 17.What is the smallest whole number by which 405 must be multiplied to get a perfect square?
- 18.What is the sum of the first 13 odd numbers (1 + 3 + 5 + …)?
- 19.What is 18²? =
- 20.Which of these is a perfect square? (a) 223 (b) 213 (c) 196
- 21.What is the smallest whole number by which 90 must be divided to get a perfect square?
- 22.What is 74²? =
- 23.What is 86²? =
- 24.What is 54²? =
- 25.What is 70²? =
- 26.What is the sum of the first 12 odd numbers (1 + 3 + 5 + …)?
- 27.What is 20²? =
- 28.A square garden has an area of 2209 square m. How long is each side (in m)?
- 29.What is the smallest whole number by which 686 must be multiplied to get a perfect square?
- 30.What is 61²? =
- 31.What is the sum of the first 30 odd numbers (1 + 3 + 5 + …)?
- 32.What is the smallest whole number by which 128 must be multiplied to get a perfect square?
- 33.What is 46²? =
- 34.Which of these is a perfect square? (a) 160 (b) 161 (c) 144
- 35.What is √484? =
- 36.What is the smallest whole number by which 54 must be multiplied to get a perfect square?
- 37.What is the smallest whole number by which 96 must be divided to get a perfect square?
- 38.What is 75²? =
- 39.What is √1681? =
- 40.What is the sum of the first 5 odd numbers (1 + 3 + 5 + …)?
Answer key
- 169
- 7
- 8836
- 40
- 62
- 1521
- 900
- 3
- 15
- 58
- 121
- 60
- 5
- 12
- 31
- 55
- 5
- 169
- 324
- 196
- 10
- 5476
- 7396
- 2916
- 4900
- 144
- 400
- 47
- 14
- 3721
- 900
- 2
- 2116
- 144
- 22
- 6
- 6
- 5625
- 41
- 25
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