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 27 odd numbers (1 + 3 + 5 + …)?
- 2.What is √400? =
- 3.What is √2500? =
- 4.What is √6889? =
- 5.Which of these is a perfect square? (a) 1374 (b) 1369 (c) 1431
- 6.What is √9025? =
- 7.What is the smallest whole number by which 72 must be multiplied to get a perfect square?
- 8.Which of these is a perfect square? (a) 387 (b) 374 (c) 361
- 9.A square garden has an area of 2809 square m. How long is each side (in m)?
- 10.What is √3721? =
- 11.What is the smallest whole number by which 63 must be multiplied to get a perfect square?
- 12.What is √5184? =
- 13.What is the sum of the first 25 odd numbers (1 + 3 + 5 + …)?
- 14.What is 22²? =
- 15.What is the smallest whole number by which 180 must be multiplied to get a perfect square?
- 16.What is √4900? =
- 17.What is the sum of the first 5 odd numbers (1 + 3 + 5 + …)?
- 18.A square garden has an area of 900 square m. How long is each side (in m)?
- 19.What is √3481? =
- 20.What is the smallest whole number by which 208 must be multiplied to get a perfect square?
- 21.Which of these is a perfect square? (a) 873 (b) 881 (c) 841
- 22.A square garden has an area of 1444 square m. How long is each side (in m)?
- 23.A square garden has an area of 1369 square m. How long is each side (in m)?
- 24.What is 69²? =
- 25.What is the sum of the first 24 odd numbers (1 + 3 + 5 + …)?
- 26.What is √6400? =
- 27.Which of these is a perfect square? (a) 226 (b) 238 (c) 225
- 28.What is the smallest whole number by which 490 must be divided to get a perfect square?
- 29.A square garden has an area of 2116 square m. How long is each side (in m)?
- 30.How many whole numbers lie between 25² and 26²?
- 31.What is √1600? =
- 32.What is the sum of the first 15 odd numbers (1 + 3 + 5 + …)?
- 33.What is 63²? =
- 34.What is √9409? =
- 35.How many whole numbers lie between 15² and 16²?
- 36.What is √784? =
- 37.What is 53²? =
- 38.How many whole numbers lie between 35² and 36²?
- 39.What is the smallest whole number by which 27 must be divided to get a perfect square?
- 40.A square garden has an area of 676 square m. How long is each side (in m)?
Answer key
- 729
- 20
- 50
- 83
- 1369
- 95
- 2
- 361
- 53
- 61
- 7
- 72
- 625
- 484
- 5
- 70
- 25
- 30
- 59
- 13
- 841
- 38
- 37
- 4761
- 576
- 80
- 225
- 10
- 46
- 50
- 40
- 225
- 3969
- 97
- 30
- 28
- 2809
- 70
- 3
- 26
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