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 smallest whole number by which 18 must be divided to get a perfect square?
- 2.Which of these is a perfect square? (a) 103 (b) 115 (c) 100
- 3.A square garden has an area of 1521 square m. How long is each side (in m)?
- 4.A square garden has an area of 784 square m. How long is each side (in m)?
- 5.What is the smallest whole number by which 44 must be multiplied to get a perfect square?
- 6.What is √3481? =
- 7.What is 21²? =
- 8.What is the sum of the first 18 odd numbers (1 + 3 + 5 + …)?
- 9.What is 58²? =
- 10.A square garden has an area of 1764 square m. How long is each side (in m)?
- 11.What is the smallest whole number by which 567 must be multiplied to get a perfect square?
- 12.What is 12²? =
- 13.A square garden has an area of 1156 square m. How long is each side (in m)?
- 14.What is √225? =
- 15.What is the smallest whole number by which 810 must be divided to get a perfect square?
- 16.What is 29²? =
- 17.Which of these is a perfect square? (a) 445 (b) 478 (c) 441
- 18.Which of these is a perfect square? (a) 1448 (b) 1444 (c) 1494
- 19.What is the smallest whole number by which 20 must be divided to get a perfect square?
- 20.What is √7569? =
- 21.What is √361? =
- 22.Which of these is a perfect square? (a) 1420 (b) 1411 (c) 1369
- 23.A square garden has an area of 441 square m. How long is each side (in m)?
- 24.What is 24²? =
- 25.A square garden has an area of 2704 square m. How long is each side (in m)?
- 26.A square garden has an area of 25 square m. How long is each side (in m)?
- 27.What is √576? =
- 28.What is √7225? =
- 29.What is the sum of the first 10 odd numbers (1 + 3 + 5 + …)?
- 30.What is 95²? =
- 31.How many whole numbers lie between 37² and 38²?
- 32.What is the smallest whole number by which 180 must be multiplied to get a perfect square?
- 33.What is √1156? =
- 34.What is 64²? =
- 35.How many whole numbers lie between 13² and 14²?
- 36.What is √121? =
- 37.What is the smallest whole number by which 12 must be multiplied to get a perfect square?
- 38.What is 71²? =
- 39.What is 31²? =
- 40.What is √5929? =
Answer key
- 2
- 100
- 39
- 28
- 11
- 59
- 441
- 324
- 3364
- 42
- 7
- 144
- 34
- 15
- 10
- 841
- 441
- 1444
- 5
- 87
- 19
- 1369
- 21
- 576
- 52
- 5
- 24
- 85
- 100
- 9025
- 74
- 5
- 34
- 4096
- 26
- 11
- 3
- 5041
- 961
- 77
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