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Class 8 Maths Worksheet: Squares and Square Roots

Maths worksheets lesson 58: Squares and square roots · Set 521 · 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.What is 15²? =
  2. 2.What is the sum of the first 12 odd numbers (1 + 3 + 5 + …)?
  3. 3.How many whole numbers lie between 29² and 30²?
  4. 4.What is 64²? =
  5. 5.What is the sum of the first 30 odd numbers (1 + 3 + 5 + …)?
  6. 6.What is the smallest whole number by which 405 must be divided to get a perfect square?
  7. 7.What is the smallest whole number by which 539 must be multiplied to get a perfect square?
  8. 8.What is √1369? =
  9. 9.A square garden has an area of 441 square m. How long is each side (in m)?
  10. 10.Which of these is a perfect square? (a) 1592 (b) 1521 (c) 1541
  11. 11.What is √6889? =
  12. 12.Which of these is a perfect square? (a) 453 (b) 441 (c) 460
  13. 13.What is 79²? =
  14. 14.What is 41²? =
  15. 15.How many whole numbers lie between 37² and 38²?
  16. 16.What is the smallest whole number by which 24 must be multiplied to get a perfect square?
  17. 17.What is √5041? =
  18. 18.A square garden has an area of 1681 square m. How long is each side (in m)?
  19. 19.What is the sum of the first 19 odd numbers (1 + 3 + 5 + …)?
  20. 20.What is the sum of the first 27 odd numbers (1 + 3 + 5 + …)?
  21. 21.What is the smallest whole number by which 54 must be divided to get a perfect square?
  22. 22.What is 28²? =
  23. 23.How many whole numbers lie between 15² and 16²?
  24. 24.What is 44²? =
  25. 25.What is √784? =
  26. 26.What is √289? =
  27. 27.A square garden has an area of 2704 square m. How long is each side (in m)?
  28. 28.What is 29²? =
  29. 29.Which of these is a perfect square? (a) 493 (b) 488 (c) 484
  30. 30.What is the smallest whole number by which 45 must be multiplied to get a perfect square?
  31. 31.What is the sum of the first 8 odd numbers (1 + 3 + 5 + …)?
  32. 32.A square garden has an area of 484 square m. How long is each side (in m)?
  33. 33.What is the sum of the first 29 odd numbers (1 + 3 + 5 + …)?
  34. 34.What is the sum of the first 11 odd numbers (1 + 3 + 5 + …)?
  35. 35.What is 46²? =
  36. 36.What is the smallest whole number by which 8 must be divided to get a perfect square?
  37. 37.How many whole numbers lie between 32² and 33²?
  38. 38.How many whole numbers lie between 26² and 27²?
  39. 39.What is the sum of the first 16 odd numbers (1 + 3 + 5 + …)?
  40. 40.What is √4624? =

Answer key

  1. 225
  2. 144
  3. 58
  4. 4096
  5. 900
  6. 5
  7. 11
  8. 37
  9. 21
  10. 1521
  11. 83
  12. 441
  13. 6241
  14. 1681
  15. 74
  16. 6
  17. 71
  18. 41
  19. 361
  20. 729
  21. 6
  22. 784
  23. 30
  24. 1936
  25. 28
  26. 17
  27. 52
  28. 841
  29. 484
  30. 5
  31. 64
  32. 22
  33. 841
  34. 121
  35. 2116
  36. 2
  37. 64
  38. 52
  39. 256
  40. 68

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