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Class 8 Maths Worksheet: Squares and Square Roots

Maths worksheets lesson 58: Squares and square roots · Set 514 · 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 the sum of the first 18 odd numbers (1 + 3 + 5 + …)?
  2. 2.What is the smallest whole number by which 540 must be divided to get a perfect square?
  3. 3.What is √1296? =
  4. 4.How many whole numbers lie between 5² and 6²?
  5. 5.What is √625? =
  6. 6.What is the sum of the first 23 odd numbers (1 + 3 + 5 + …)?
  7. 7.What is the sum of the first 17 odd numbers (1 + 3 + 5 + …)?
  8. 8.What is the sum of the first 28 odd numbers (1 + 3 + 5 + …)?
  9. 9.How many whole numbers lie between 44² and 45²?
  10. 10.What is the sum of the first 6 odd numbers (1 + 3 + 5 + …)?
  11. 11.What is 15²? =
  12. 12.What is √8649? =
  13. 13.What is 74²? =
  14. 14.What is 17²? =
  15. 15.What is 79²? =
  16. 16.What is the smallest whole number by which 1134 must be divided to get a perfect square?
  17. 17.What is 60²? =
  18. 18.A square garden has an area of 225 square m. How long is each side (in m)?
  19. 19.What is 64²? =
  20. 20.What is 34²? =
  21. 21.What is the sum of the first 5 odd numbers (1 + 3 + 5 + …)?
  22. 22.What is the smallest whole number by which 125 must be multiplied to get a perfect square?
  23. 23.What is √6084? =
  24. 24.How many whole numbers lie between 30² and 31²?
  25. 25.What is 25²? =
  26. 26.A square garden has an area of 196 square m. How long is each side (in m)?
  27. 27.How many whole numbers lie between 35² and 36²?
  28. 28.What is √484? =
  29. 29.Which of these is a perfect square? (a) 841 (b) 860 (c) 869
  30. 30.How many whole numbers lie between 31² and 32²?
  31. 31.What is √3969? =
  32. 32.What is √6241? =
  33. 33.What is √4225? =
  34. 34.What is √256? =
  35. 35.What is the smallest whole number by which 162 must be multiplied to get a perfect square?
  36. 36.What is the sum of the first 7 odd numbers (1 + 3 + 5 + …)?
  37. 37.A square garden has an area of 2209 square m. How long is each side (in m)?
  38. 38.What is 21²? =
  39. 39.What is the smallest whole number by which 75 must be multiplied to get a perfect square?
  40. 40.What is the sum of the first 12 odd numbers (1 + 3 + 5 + …)?

Answer key

  1. 324
  2. 15
  3. 36
  4. 10
  5. 25
  6. 529
  7. 289
  8. 784
  9. 88
  10. 36
  11. 225
  12. 93
  13. 5476
  14. 289
  15. 6241
  16. 14
  17. 3600
  18. 15
  19. 4096
  20. 1156
  21. 25
  22. 5
  23. 78
  24. 60
  25. 625
  26. 14
  27. 70
  28. 22
  29. 841
  30. 62
  31. 63
  32. 79
  33. 65
  34. 16
  35. 2
  36. 49
  37. 47
  38. 441
  39. 3
  40. 144

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