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Class 8 Maths Worksheet: Squares and Square Roots

Maths worksheets lesson 58: Squares and square roots · Set 192 · 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.How many whole numbers lie between 39² and 40²?
  2. 2.What is √4225? =
  3. 3.What is √9216? =
  4. 4.A square garden has an area of 2809 square m. How long is each side (in m)?
  5. 5.Which of these is a perfect square? (a) 292 (b) 289 (c) 323
  6. 6.Which of these is a perfect square? (a) 1104 (b) 1100 (c) 1089
  7. 7.What is 28²? =
  8. 8.How many whole numbers lie between 14² and 15²?
  9. 9.Which of these is a perfect square? (a) 594 (b) 587 (c) 576
  10. 10.What is 33²? =
  11. 11.What is the sum of the first 7 odd numbers (1 + 3 + 5 + …)?
  12. 12.A square garden has an area of 100 square m. How long is each side (in m)?
  13. 13.What is √196? =
  14. 14.What is the smallest whole number by which 160 must be divided to get a perfect square?
  15. 15.What is the sum of the first 9 odd numbers (1 + 3 + 5 + …)?
  16. 16.How many whole numbers lie between 42² and 43²?
  17. 17.What is 31²? =
  18. 18.Which of these is a perfect square? (a) 159 (b) 160 (c) 144
  19. 19.What is the sum of the first 17 odd numbers (1 + 3 + 5 + …)?
  20. 20.What is the sum of the first 20 odd numbers (1 + 3 + 5 + …)?
  21. 21.How many whole numbers lie between 33² and 34²?
  22. 22.A square garden has an area of 1225 square m. How long is each side (in m)?
  23. 23.What is 62²? =
  24. 24.A square garden has an area of 1024 square m. How long is each side (in m)?
  25. 25.What is 68²? =
  26. 26.What is √8464? =
  27. 27.What is √8649? =
  28. 28.What is √8100? =
  29. 29.What is 67²? =
  30. 30.Which of these is a perfect square? (a) 1653 (b) 1652 (c) 1600
  31. 31.What is the smallest whole number by which 32 must be divided to get a perfect square?
  32. 32.What is the sum of the first 28 odd numbers (1 + 3 + 5 + …)?
  33. 33.What is 75²? =
  34. 34.What is the smallest whole number by which 896 must be divided to get a perfect square?
  35. 35.What is 70²? =
  36. 36.How many whole numbers lie between 37² and 38²?
  37. 37.Which of these is a perfect square? (a) 130 (b) 135 (c) 121
  38. 38.What is 63²? =
  39. 39.How many whole numbers lie between 32² and 33²?
  40. 40.Which of these is a perfect square? (a) 377 (b) 383 (c) 361

Answer key

  1. 78
  2. 65
  3. 96
  4. 53
  5. 289
  6. 1089
  7. 784
  8. 28
  9. 576
  10. 1089
  11. 49
  12. 10
  13. 14
  14. 10
  15. 81
  16. 84
  17. 961
  18. 144
  19. 289
  20. 400
  21. 66
  22. 35
  23. 3844
  24. 32
  25. 4624
  26. 92
  27. 93
  28. 90
  29. 4489
  30. 1600
  31. 2
  32. 784
  33. 5625
  34. 14
  35. 4900
  36. 74
  37. 121
  38. 3969
  39. 64
  40. 361

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