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Class 8 Maths Worksheet: Squares and Square Roots

Maths worksheets lesson 58: Squares and square roots · Set 4 · 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 12 odd numbers (1 + 3 + 5 + …)?
  2. 2.How many whole numbers lie between 34² and 35²?
  3. 3.Which of these is a perfect square? (a) 704 (b) 707 (c) 676
  4. 4.What is the smallest whole number by which 1215 must be divided to get a perfect square?
  5. 5.What is the sum of the first 19 odd numbers (1 + 3 + 5 + …)?
  6. 6.What is 87²? =
  7. 7.What is the smallest whole number by which 448 must be divided to get a perfect square?
  8. 8.What is the smallest whole number by which 99 must be multiplied to get a perfect square?
  9. 9.How many whole numbers lie between 37² and 38²?
  10. 10.Which of these is a perfect square? (a) 1645 (b) 1643 (c) 1600
  11. 11.What is √1156? =
  12. 12.What is √9216? =
  13. 13.What is 62²? =
  14. 14.Which of these is a perfect square? (a) 1156 (b) 1167 (c) 1189
  15. 15.What is the smallest whole number by which 686 must be multiplied to get a perfect square?
  16. 16.What is √144? =
  17. 17.What is the sum of the first 11 odd numbers (1 + 3 + 5 + …)?
  18. 18.What is the smallest whole number by which 208 must be divided to get a perfect square?
  19. 19.Which of these is a perfect square? (a) 214 (b) 208 (c) 196
  20. 20.What is √729? =
  21. 21.Which of these is a perfect square? (a) 525 (b) 484 (c) 488
  22. 22.How many whole numbers lie between 15² and 16²?
  23. 23.What is the smallest whole number by which 360 must be multiplied to get a perfect square?
  24. 24.Which of these is a perfect square? (a) 798 (b) 801 (c) 784
  25. 25.What is 45²? =
  26. 26.What is 56²? =
  27. 27.How many whole numbers lie between 43² and 44²?
  28. 28.What is the smallest whole number by which 98 must be divided to get a perfect square?
  29. 29.What is √6241? =
  30. 30.What is the smallest whole number by which 50 must be multiplied to get a perfect square?
  31. 31.Which of these is a perfect square? (a) 138 (b) 128 (c) 121
  32. 32.What is 73²? =
  33. 33.How many whole numbers lie between 27² and 28²?
  34. 34.What is 65²? =
  35. 35.Which of these is a perfect square? (a) 320 (b) 289 (c) 299
  36. 36.What is the smallest whole number by which 1134 must be divided to get a perfect square?
  37. 37.What is the sum of the first 13 odd numbers (1 + 3 + 5 + …)?
  38. 38.How many whole numbers lie between 46² and 47²?
  39. 39.What is the sum of the first 24 odd numbers (1 + 3 + 5 + …)?
  40. 40.What is the sum of the first 7 odd numbers (1 + 3 + 5 + …)?

Answer key

  1. 144
  2. 68
  3. 676
  4. 15
  5. 361
  6. 7569
  7. 7
  8. 11
  9. 74
  10. 1600
  11. 34
  12. 96
  13. 3844
  14. 1156
  15. 14
  16. 12
  17. 121
  18. 13
  19. 196
  20. 27
  21. 484
  22. 30
  23. 10
  24. 784
  25. 2025
  26. 3136
  27. 86
  28. 2
  29. 79
  30. 2
  31. 121
  32. 5329
  33. 54
  34. 4225
  35. 289
  36. 14
  37. 169
  38. 92
  39. 576
  40. 49

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