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Class 8 Maths Worksheet: Squares and Square Roots

Maths worksheets lesson 58: Squares and square roots · Set 451 · 40 sums
TalentJR

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. 1.A square garden has an area of 361 square m. How long is each side (in m)?
  2. 2.What is 48²? =
  3. 3.What is √1089? =
  4. 4.What is the sum of the first 26 odd numbers (1 + 3 + 5 + …)?
  5. 5.What is the sum of the first 14 odd numbers (1 + 3 + 5 + …)?
  6. 6.What is 65²? =
  7. 7.What is the smallest whole number by which 135 must be multiplied to get a perfect square?
  8. 8.What is the smallest whole number by which 243 must be multiplied to get a perfect square?
  9. 9.How many whole numbers lie between 20² and 21²?
  10. 10.Which of these is a perfect square? (a) 555 (b) 529 (c) 570
  11. 11.What is the sum of the first 23 odd numbers (1 + 3 + 5 + …)?
  12. 12.How many whole numbers lie between 7² and 8²?
  13. 13.What is 23²? =
  14. 14.What is 83²? =
  15. 15.A square garden has an area of 1849 square m. How long is each side (in m)?
  16. 16.How many whole numbers lie between 5² and 6²?
  17. 17.How many whole numbers lie between 38² and 39²?
  18. 18.What is the sum of the first 22 odd numbers (1 + 3 + 5 + …)?
  19. 19.Which of these is a perfect square? (a) 441 (b) 443 (c) 453
  20. 20.What is √9409? =
  21. 21.How many whole numbers lie between 49² and 50²?
  22. 22.What is 62²? =
  23. 23.What is 73²? =
  24. 24.How many whole numbers lie between 46² and 47²?
  25. 25.How many whole numbers lie between 10² and 11²?
  26. 26.Which of these is a perfect square? (a) 668 (b) 625 (c) 650
  27. 27.How many whole numbers lie between 37² and 38²?
  28. 28.What is √784? =
  29. 29.What is √2116? =
  30. 30.What is √121? =
  31. 31.What is the smallest whole number by which 704 must be multiplied to get a perfect square?
  32. 32.What is √8836? =
  33. 33.Which of these is a perfect square? (a) 330 (b) 342 (c) 324
  34. 34.What is 99²? =
  35. 35.A square garden has an area of 225 square m. How long is each side (in m)?
  36. 36.What is 36²? =
  37. 37.What is the sum of the first 21 odd numbers (1 + 3 + 5 + …)?
  38. 38.What is the smallest whole number by which 176 must be multiplied to get a perfect square?
  39. 39.What is √6241? =
  40. 40.What is 88²? =

Answer key

  1. 19
  2. 2304
  3. 33
  4. 676
  5. 196
  6. 4225
  7. 15
  8. 3
  9. 40
  10. 529
  11. 529
  12. 14
  13. 529
  14. 6889
  15. 43
  16. 10
  17. 76
  18. 484
  19. 441
  20. 97
  21. 98
  22. 3844
  23. 5329
  24. 92
  25. 20
  26. 625
  27. 74
  28. 28
  29. 46
  30. 11
  31. 11
  32. 94
  33. 324
  34. 9801
  35. 15
  36. 1296
  37. 441
  38. 11
  39. 79
  40. 7744

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