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Class 8 Maths Worksheet: Squares and Square Roots

Maths worksheets lesson 58: Squares and square roots · Set 361 · 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 √9025? =
  2. 2.What is the smallest whole number by which 48 must be divided to get a perfect square?
  3. 3.What is √3136? =
  4. 4.A square garden has an area of 3481 square m. How long is each side (in m)?
  5. 5.What is 79²? =
  6. 6.What is the sum of the first 23 odd numbers (1 + 3 + 5 + …)?
  7. 7.A square garden has an area of 1681 square m. How long is each side (in m)?
  8. 8.What is √3025? =
  9. 9.What is 61²? =
  10. 10.Which of these is a perfect square? (a) 230 (b) 225 (c) 235
  11. 11.What is 88²? =
  12. 12.Which of these is a perfect square? (a) 484 (b) 485 (c) 488
  13. 13.What is 70²? =
  14. 14.Which of these is a perfect square? (a) 689 (b) 676 (c) 679
  15. 15.What is 38²? =
  16. 16.What is the smallest whole number by which 1053 must be multiplied to get a perfect square?
  17. 17.Which of these is a perfect square? (a) 400 (b) 410 (c) 405
  18. 18.What is √324? =
  19. 19.What is √1156? =
  20. 20.What is √625? =
  21. 21.What is √3249? =
  22. 22.Which of these is a perfect square? (a) 576 (b) 605 (c) 584
  23. 23.What is the smallest whole number by which 245 must be divided to get a perfect square?
  24. 24.What is 14²? =
  25. 25.Which of these is a perfect square? (a) 144 (b) 167 (c) 153
  26. 26.What is the sum of the first 5 odd numbers (1 + 3 + 5 + …)?
  27. 27.Which of these is a perfect square? (a) 1146 (b) 1119 (c) 1089
  28. 28.What is √121? =
  29. 29.What is the smallest whole number by which 117 must be multiplied to get a perfect square?
  30. 30.What is the smallest whole number by which 1134 must be divided to get a perfect square?
  31. 31.Which of these is a perfect square? (a) 1546 (b) 1592 (c) 1521
  32. 32.What is √784? =
  33. 33.How many whole numbers lie between 18² and 19²?
  34. 34.What is the smallest whole number by which 8 must be divided to get a perfect square?
  35. 35.What is the smallest whole number by which 60 must be divided to get a perfect square?
  36. 36.What is 37²? =
  37. 37.What is 21²? =
  38. 38.What is √4624? =
  39. 39.How many whole numbers lie between 12² and 13²?
  40. 40.What is the smallest whole number by which 160 must be multiplied to get a perfect square?

Answer key

  1. 95
  2. 3
  3. 56
  4. 59
  5. 6241
  6. 529
  7. 41
  8. 55
  9. 3721
  10. 225
  11. 7744
  12. 484
  13. 4900
  14. 676
  15. 1444
  16. 13
  17. 400
  18. 18
  19. 34
  20. 25
  21. 57
  22. 576
  23. 5
  24. 196
  25. 144
  26. 25
  27. 1089
  28. 11
  29. 13
  30. 14
  31. 1521
  32. 28
  33. 36
  34. 2
  35. 15
  36. 1369
  37. 441
  38. 68
  39. 24
  40. 10

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