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 2401 square m. How long is each side (in m)?
- 2.What is 43²? =
- 3.What is the smallest whole number by which 275 must be divided to get a perfect square?
- 4.What is 28²? =
- 5.What is √3844? =
- 6.What is √4489? =
- 7.What is √625? =
- 8.What is 25²? =
- 9.A square garden has an area of 289 square m. How long is each side (in m)?
- 10.What is 62²? =
- 11.What is the sum of the first 20 odd numbers (1 + 3 + 5 + …)?
- 12.What is the smallest whole number by which 250 must be multiplied to get a perfect square?
- 13.Which of these is a perfect square? (a) 755 (b) 742 (c) 729
- 14.Which of these is a perfect square? (a) 208 (b) 196 (c) 200
- 15.What is the sum of the first 13 odd numbers (1 + 3 + 5 + …)?
- 16.Which of these is a perfect square? (a) 1442 (b) 1374 (c) 1369
- 17.What is 99²? =
- 18.A square garden has an area of 441 square m. How long is each side (in m)?
- 19.What is 15²? =
- 20.What is the smallest whole number by which 243 must be divided to get a perfect square?
- 21.What is √5625? =
- 22.What is the smallest whole number by which 63 must be multiplied to get a perfect square?
- 23.What is 42²? =
- 24.Which of these is a perfect square? (a) 1296 (b) 1343 (c) 1314
- 25.How many whole numbers lie between 44² and 45²?
- 26.What is √169? =
- 27.A square garden has an area of 576 square m. How long is each side (in m)?
- 28.What is the smallest whole number by which 486 must be multiplied to get a perfect square?
- 29.A square garden has an area of 3249 square m. How long is each side (in m)?
- 30.What is the sum of the first 10 odd numbers (1 + 3 + 5 + …)?
- 31.What is 57²? =
- 32.Which of these is a perfect square? (a) 146 (b) 160 (c) 144
- 33.What is the sum of the first 23 odd numbers (1 + 3 + 5 + …)?
- 34.How many whole numbers lie between 22² and 23²?
- 35.What is the smallest whole number by which 1215 must be divided to get a perfect square?
- 36.What is 21²? =
- 37.What is the sum of the first 15 odd numbers (1 + 3 + 5 + …)?
- 38.What is the smallest whole number by which 52 must be multiplied to get a perfect square?
- 39.What is √289? =
- 40.Which of these is a perfect square? (a) 616 (b) 615 (c) 576
Answer key
- 49
- 1849
- 11
- 784
- 62
- 67
- 25
- 625
- 17
- 3844
- 400
- 10
- 729
- 196
- 169
- 1369
- 9801
- 21
- 225
- 3
- 75
- 7
- 1764
- 1296
- 88
- 13
- 24
- 6
- 57
- 100
- 3249
- 144
- 529
- 44
- 15
- 441
- 225
- 13
- 17
- 576
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