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.How many whole numbers lie between 11² and 12²?
- 2.What is the smallest whole number by which 27 must be divided to get a perfect square?
- 3.Which of these is a perfect square? (a) 121 (b) 131 (c) 126
- 4.What is the sum of the first 29 odd numbers (1 + 3 + 5 + …)?
- 5.How many whole numbers lie between 49² and 50²?
- 6.Which of these is a perfect square? (a) 109 (b) 100 (c) 112
- 7.What is √7921? =
- 8.What is √3600? =
- 9.What is 61²? =
- 10.How many whole numbers lie between 43² and 44²?
- 11.A square garden has an area of 3481 square m. How long is each side (in m)?
- 12.What is 31²? =
- 13.What is the sum of the first 30 odd numbers (1 + 3 + 5 + …)?
- 14.What is √529? =
- 15.What is 98²? =
- 16.What is the smallest whole number by which 160 must be multiplied to get a perfect square?
- 17.What is √841? =
- 18.What is the sum of the first 13 odd numbers (1 + 3 + 5 + …)?
- 19.Which of these is a perfect square? (a) 1584 (b) 1521 (c) 1544
- 20.What is 17²? =
- 21.What is √4356? =
- 22.What is 78²? =
- 23.A square garden has an area of 484 square m. How long is each side (in m)?
- 24.Which of these is a perfect square? (a) 1388 (b) 1369 (c) 1387
- 25.What is 90²? =
- 26.How many whole numbers lie between 25² and 26²?
- 27.How many whole numbers lie between 37² and 38²?
- 28.What is √1936? =
- 29.A square garden has an area of 1764 square m. How long is each side (in m)?
- 30.What is √7225? =
- 31.What is the sum of the first 28 odd numbers (1 + 3 + 5 + …)?
- 32.Which of these is a perfect square? (a) 951 (b) 900 (c) 912
- 33.What is 52²? =
- 34.What is the smallest whole number by which 320 must be divided to get a perfect square?
- 35.What is the sum of the first 11 odd numbers (1 + 3 + 5 + …)?
- 36.What is 37²? =
- 37.What is the sum of the first 17 odd numbers (1 + 3 + 5 + …)?
- 38.A square garden has an area of 625 square m. How long is each side (in m)?
- 39.How many whole numbers lie between 40² and 41²?
- 40.A square garden has an area of 841 square m. How long is each side (in m)?
Answer key
- 22
- 3
- 121
- 841
- 98
- 100
- 89
- 60
- 3721
- 86
- 59
- 961
- 900
- 23
- 9604
- 10
- 29
- 169
- 1521
- 289
- 66
- 6084
- 22
- 1369
- 8100
- 50
- 74
- 44
- 42
- 85
- 784
- 900
- 2704
- 5
- 121
- 1369
- 289
- 25
- 80
- 29
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