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Class 8 Maths Worksheet: Squares and Square Roots

Maths worksheets lesson 58: Squares and square roots · Set 43 · 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.A square garden has an area of 729 square m. How long is each side (in m)?
  2. 2.What is 83²? =
  3. 3.What is the sum of the first 9 odd numbers (1 + 3 + 5 + …)?
  4. 4.What is 80²? =
  5. 5.Which of these is a perfect square? (a) 403 (b) 417 (c) 400
  6. 6.What is the sum of the first 21 odd numbers (1 + 3 + 5 + …)?
  7. 7.What is √576? =
  8. 8.Which of these is a perfect square? (a) 1265 (b) 1234 (c) 1225
  9. 9.What is 98²? =
  10. 10.What is the smallest whole number by which 245 must be divided to get a perfect square?
  11. 11.What is 29²? =
  12. 12.What is √441? =
  13. 13.What is the smallest whole number by which 250 must be divided to get a perfect square?
  14. 14.How many whole numbers lie between 6² and 7²?
  15. 15.How many whole numbers lie between 18² and 19²?
  16. 16.What is 87²? =
  17. 17.What is 86²? =
  18. 18.How many whole numbers lie between 39² and 40²?
  19. 19.A square garden has an area of 3249 square m. How long is each side (in m)?
  20. 20.What is 35²? =
  21. 21.How many whole numbers lie between 16² and 17²?
  22. 22.What is the sum of the first 6 odd numbers (1 + 3 + 5 + …)?
  23. 23.What is √8464? =
  24. 24.How many whole numbers lie between 25² and 26²?
  25. 25.How many whole numbers lie between 48² and 49²?
  26. 26.What is √1600? =
  27. 27.What is 51²? =
  28. 28.What is 57²? =
  29. 29.What is 49²? =
  30. 30.What is 31²? =
  31. 31.How many whole numbers lie between 17² and 18²?
  32. 32.What is the smallest whole number by which 12 must be multiplied to get a perfect square?
  33. 33.What is the sum of the first 12 odd numbers (1 + 3 + 5 + …)?
  34. 34.Which of these is a perfect square? (a) 1082 (b) 1059 (c) 1024
  35. 35.What is the smallest whole number by which 468 must be divided to get a perfect square?
  36. 36.A square garden has an area of 225 square m. How long is each side (in m)?
  37. 37.What is 22²? =
  38. 38.How many whole numbers lie between 45² and 46²?
  39. 39.What is the smallest whole number by which 98 must be multiplied to get a perfect square?
  40. 40.How many whole numbers lie between 5² and 6²?

Answer key

  1. 27
  2. 6889
  3. 81
  4. 6400
  5. 400
  6. 441
  7. 24
  8. 1225
  9. 9604
  10. 5
  11. 841
  12. 21
  13. 10
  14. 12
  15. 36
  16. 7569
  17. 7396
  18. 78
  19. 57
  20. 1225
  21. 32
  22. 36
  23. 92
  24. 50
  25. 96
  26. 40
  27. 2601
  28. 3249
  29. 2401
  30. 961
  31. 34
  32. 3
  33. 144
  34. 1024
  35. 13
  36. 15
  37. 484
  38. 90
  39. 2
  40. 10

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