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Class 8 Maths Worksheet: Squares and Square Roots

Maths worksheets lesson 58: Squares and square roots · Set 732 · 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.Which of these is a perfect square? (a) 643 (b) 625 (c) 634
  2. 2.What is the smallest whole number by which 640 must be multiplied to get a perfect square?
  3. 3.What is the smallest whole number by which 810 must be multiplied to get a perfect square?
  4. 4.What is 92²? =
  5. 5.What is √729? =
  6. 6.A square garden has an area of 1681 square m. How long is each side (in m)?
  7. 7.How many whole numbers lie between 12² and 13²?
  8. 8.What is 74²? =
  9. 9.What is the smallest whole number by which 90 must be multiplied to get a perfect square?
  10. 10.What is √144? =
  11. 11.What is 47²? =
  12. 12.Which of these is a perfect square? (a) 864 (b) 841 (c) 888
  13. 13.What is √484? =
  14. 14.Which of these is a perfect square? (a) 364 (b) 361 (c) 370
  15. 15.A square garden has an area of 2116 square m. How long is each side (in m)?
  16. 16.What is √6561? =
  17. 17.What is √8100? =
  18. 18.What is the sum of the first 13 odd numbers (1 + 3 + 5 + …)?
  19. 19.What is √7056? =
  20. 20.How many whole numbers lie between 9² and 10²?
  21. 21.How many whole numbers lie between 5² and 6²?
  22. 22.What is 12²? =
  23. 23.What is the sum of the first 24 odd numbers (1 + 3 + 5 + …)?
  24. 24.What is the smallest whole number by which 240 must be divided to get a perfect square?
  25. 25.What is 27²? =
  26. 26.How many whole numbers lie between 17² and 18²?
  27. 27.What is 43²? =
  28. 28.What is the sum of the first 6 odd numbers (1 + 3 + 5 + …)?
  29. 29.Which of these is a perfect square? (a) 620 (b) 623 (c) 576
  30. 30.What is the sum of the first 28 odd numbers (1 + 3 + 5 + …)?
  31. 31.What is 97²? =
  32. 32.How many whole numbers lie between 30² and 31²?
  33. 33.What is the smallest whole number by which 539 must be multiplied to get a perfect square?
  34. 34.What is √4761? =
  35. 35.How many whole numbers lie between 39² and 40²?
  36. 36.What is the sum of the first 15 odd numbers (1 + 3 + 5 + …)?
  37. 37.What is 46²? =
  38. 38.What is 85²? =
  39. 39.What is √8281? =
  40. 40.What is the sum of the first 29 odd numbers (1 + 3 + 5 + …)?

Answer key

  1. 625
  2. 10
  3. 10
  4. 8464
  5. 27
  6. 41
  7. 24
  8. 5476
  9. 10
  10. 12
  11. 2209
  12. 841
  13. 22
  14. 361
  15. 46
  16. 81
  17. 90
  18. 169
  19. 84
  20. 18
  21. 10
  22. 144
  23. 576
  24. 15
  25. 729
  26. 34
  27. 1849
  28. 36
  29. 576
  30. 784
  31. 9409
  32. 60
  33. 11
  34. 69
  35. 78
  36. 225
  37. 2116
  38. 7225
  39. 91
  40. 841

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