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Class 8 Maths Worksheet: Squares and Square Roots

Maths worksheets lesson 58: Squares and square roots · Set 536 · 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 √3249? =
  2. 2.What is 49²? =
  3. 3.What is the sum of the first 13 odd numbers (1 + 3 + 5 + …)?
  4. 4.Which of these is a perfect square? (a) 241 (b) 225 (c) 248
  5. 5.What is 83²? =
  6. 6.How many whole numbers lie between 48² and 49²?
  7. 7.What is the sum of the first 10 odd numbers (1 + 3 + 5 + …)?
  8. 8.What is 30²? =
  9. 9.How many whole numbers lie between 9² and 10²?
  10. 10.How many whole numbers lie between 7² and 8²?
  11. 11.What is the sum of the first 20 odd numbers (1 + 3 + 5 + …)?
  12. 12.What is the smallest whole number by which 360 must be multiplied to get a perfect square?
  13. 13.What is √400? =
  14. 14.What is the sum of the first 19 odd numbers (1 + 3 + 5 + …)?
  15. 15.How many whole numbers lie between 39² and 40²?
  16. 16.A square garden has an area of 64 square m. How long is each side (in m)?
  17. 17.What is 54²? =
  18. 18.What is √2025? =
  19. 19.What is the sum of the first 28 odd numbers (1 + 3 + 5 + …)?
  20. 20.What is √1849? =
  21. 21.What is 55²? =
  22. 22.A square garden has an area of 1764 square m. How long is each side (in m)?
  23. 23.What is √4624? =
  24. 24.What is √1089? =
  25. 25.What is the sum of the first 14 odd numbers (1 + 3 + 5 + …)?
  26. 26.What is the sum of the first 30 odd numbers (1 + 3 + 5 + …)?
  27. 27.What is √576? =
  28. 28.What is 69²? =
  29. 29.What is 23²? =
  30. 30.Which of these is a perfect square? (a) 186 (b) 179 (c) 169
  31. 31.What is the sum of the first 29 odd numbers (1 + 3 + 5 + …)?
  32. 32.A square garden has an area of 1444 square m. How long is each side (in m)?
  33. 33.What is 80²? =
  34. 34.A square garden has an area of 256 square m. How long is each side (in m)?
  35. 35.How many whole numbers lie between 6² and 7²?
  36. 36.What is the sum of the first 15 odd numbers (1 + 3 + 5 + …)?
  37. 37.How many whole numbers lie between 47² and 48²?
  38. 38.What is the smallest whole number by which 240 must be multiplied to get a perfect square?
  39. 39.What is √324? =
  40. 40.What is the smallest whole number by which 486 must be multiplied to get a perfect square?

Answer key

  1. 57
  2. 2401
  3. 169
  4. 225
  5. 6889
  6. 96
  7. 100
  8. 900
  9. 18
  10. 14
  11. 400
  12. 10
  13. 20
  14. 361
  15. 78
  16. 8
  17. 2916
  18. 45
  19. 784
  20. 43
  21. 3025
  22. 42
  23. 68
  24. 33
  25. 196
  26. 900
  27. 24
  28. 4761
  29. 529
  30. 169
  31. 841
  32. 38
  33. 6400
  34. 16
  35. 12
  36. 225
  37. 94
  38. 15
  39. 18
  40. 6

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