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 √2809? =
- 2.What is the smallest whole number by which 468 must be multiplied to get a perfect square?
- 3.What is the sum of the first 22 odd numbers (1 + 3 + 5 + …)?
- 4.What is 81²? =
- 5.What is √3136? =
- 6.What is the sum of the first 6 odd numbers (1 + 3 + 5 + …)?
- 7.How many whole numbers lie between 9² and 10²?
- 8.What is the sum of the first 8 odd numbers (1 + 3 + 5 + …)?
- 9.Which of these is a perfect square? (a) 543 (b) 539 (c) 529
- 10.A square garden has an area of 2116 square m. How long is each side (in m)?
- 11.How many whole numbers lie between 14² and 15²?
- 12.What is the sum of the first 18 odd numbers (1 + 3 + 5 + …)?
- 13.Which of these is a perfect square? (a) 130 (b) 143 (c) 121
- 14.What is √3721? =
- 15.What is the smallest whole number by which 224 must be multiplied to get a perfect square?
- 16.How many whole numbers lie between 46² and 47²?
- 17.What is √4761? =
- 18.A square garden has an area of 841 square m. How long is each side (in m)?
- 19.A square garden has an area of 2025 square m. How long is each side (in m)?
- 20.What is the sum of the first 9 odd numbers (1 + 3 + 5 + …)?
- 21.What is the smallest whole number by which 20 must be divided to get a perfect square?
- 22.What is the smallest whole number by which 704 must be multiplied to get a perfect square?
- 23.What is the smallest whole number by which 540 must be divided to get a perfect square?
- 24.What is √324? =
- 25.What is √4489? =
- 26.How many whole numbers lie between 29² and 30²?
- 27.What is the smallest whole number by which 325 must be divided to get a perfect square?
- 28.What is √3249? =
- 29.What is 16²? =
- 30.What is 30²? =
- 31.Which of these is a perfect square? (a) 106 (b) 103 (c) 100
- 32.What is √169? =
- 33.What is 54²? =
- 34.A square garden has an area of 49 square m. How long is each side (in m)?
- 35.What is the sum of the first 19 odd numbers (1 + 3 + 5 + …)?
- 36.How many whole numbers lie between 42² and 43²?
- 37.What is the smallest whole number by which 20 must be multiplied to get a perfect square?
- 38.Which of these is a perfect square? (a) 326 (b) 324 (c) 355
- 39.What is √1681? =
- 40.What is the sum of the first 26 odd numbers (1 + 3 + 5 + …)?
Answer key
- 53
- 13
- 484
- 6561
- 56
- 36
- 18
- 64
- 529
- 46
- 28
- 324
- 121
- 61
- 14
- 92
- 69
- 29
- 45
- 81
- 5
- 11
- 15
- 18
- 67
- 58
- 13
- 57
- 256
- 900
- 100
- 13
- 2916
- 7
- 361
- 84
- 5
- 324
- 41
- 676
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