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Class 8 Maths Worksheet: Squares and Square Roots

Maths worksheets lesson 58: Squares and square roots · Set 545 · 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 20²? =
  2. 2.Which of these is a perfect square? (a) 1156 (b) 1201 (c) 1210
  3. 3.What is the smallest whole number by which 48 must be multiplied to get a perfect square?
  4. 4.What is the sum of the first 30 odd numbers (1 + 3 + 5 + …)?
  5. 5.What is 52²? =
  6. 6.What is the smallest whole number by which 637 must be multiplied to get a perfect square?
  7. 7.What is the sum of the first 7 odd numbers (1 + 3 + 5 + …)?
  8. 8.What is 58²? =
  9. 9.What is √1521? =
  10. 10.How many whole numbers lie between 16² and 17²?
  11. 11.What is 97²? =
  12. 12.Which of these is a perfect square? (a) 248 (b) 236 (c) 225
  13. 13.What is 83²? =
  14. 14.What is the sum of the first 5 odd numbers (1 + 3 + 5 + …)?
  15. 15.What is the sum of the first 9 odd numbers (1 + 3 + 5 + …)?
  16. 16.What is √400? =
  17. 17.What is 25²? =
  18. 18.How many whole numbers lie between 46² and 47²?
  19. 19.What is 29²? =
  20. 20.What is √6400? =
  21. 21.A square garden has an area of 324 square m. How long is each side (in m)?
  22. 22.What is 66²? =
  23. 23.How many whole numbers lie between 35² and 36²?
  24. 24.What is 85²? =
  25. 25.What is the sum of the first 15 odd numbers (1 + 3 + 5 + …)?
  26. 26.What is 30²? =
  27. 27.What is √1225? =
  28. 28.What is the sum of the first 18 odd numbers (1 + 3 + 5 + …)?
  29. 29.What is √5041? =
  30. 30.What is 86²? =
  31. 31.How many whole numbers lie between 40² and 41²?
  32. 32.How many whole numbers lie between 49² and 50²?
  33. 33.What is the smallest whole number by which 810 must be multiplied to get a perfect square?
  34. 34.A square garden has an area of 196 square m. How long is each side (in m)?
  35. 35.Which of these is a perfect square? (a) 574 (b) 529 (c) 547
  36. 36.What is 18²? =
  37. 37.What is 94²? =
  38. 38.How many whole numbers lie between 5² and 6²?
  39. 39.What is the sum of the first 17 odd numbers (1 + 3 + 5 + …)?
  40. 40.A square garden has an area of 144 square m. How long is each side (in m)?

Answer key

  1. 400
  2. 1156
  3. 3
  4. 900
  5. 2704
  6. 13
  7. 49
  8. 3364
  9. 39
  10. 32
  11. 9409
  12. 225
  13. 6889
  14. 25
  15. 81
  16. 20
  17. 625
  18. 92
  19. 841
  20. 80
  21. 18
  22. 4356
  23. 70
  24. 7225
  25. 225
  26. 900
  27. 35
  28. 324
  29. 71
  30. 7396
  31. 80
  32. 98
  33. 10
  34. 14
  35. 529
  36. 324
  37. 8836
  38. 10
  39. 289
  40. 12

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