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Class 8 Maths Worksheet: Cubes and Cube Roots

Maths worksheets lesson 59: Cubes and cube roots · Set 708 · 40 sums
TalentJR

The method (Threes make cubes): Cube: n × n × n. Cube root: the number that, used three times, gives the cube. Units digits: 1→1, 2→8, 3→7, 4→4, 5→5, 6→6, 7→3, 8→2, 9→9, 0→0 — use them to guess cube roots. Make a perfect cube: break into primes; multiply by what completes each group of three (or divide by what is left over). A big cube of edge a cut into small cubes of edge b gives (a ÷ b)³ small cubes.

NameDateTime takenScore ___ / 40
  1. 1.Which of these is a perfect cube? (a) 125 (b) 182 (c) 135
  2. 2.Which of these is a perfect cube? (a) 27 (b) 36 (c) 29
  3. 3.Which of these is a perfect cube? (a) 2864 (b) 3221 (c) 2744
  4. 4.What is 3³? =
  5. 5.What is ∛9261? =
  6. 6.What is 7³? =
  7. 7.What is ∛64? =
  8. 8.What is 11³? =
  9. 9.What is ∛3375? =
  10. 10.What is 5³? =
  11. 11.Which of these is a perfect cube? (a) 1798 (b) 1728 (c) 1846
  12. 12.What is the smallest whole number by which 243 must be divided to get a perfect cube?
  13. 13.What is ∛27? =
  14. 14.What is the smallest whole number by which 135 must be multiplied to get a perfect cube?
  15. 15.What is ∛512? =
  16. 16.Which of these is a perfect cube? (a) 294 (b) 235 (c) 216
  17. 17.Which of these is a perfect cube? (a) 729 (b) 787 (c) 842
  18. 18.What is ∛6859? =
  19. 19.A big cube of edge 3 cm is cut into small cubes of edge 1 cm. How many small cubes are there?
  20. 20.What is the smallest whole number by which 189 must be divided to get a perfect cube?
  21. 21.A cube has a volume of 343 cubic cm. How long is each edge (in cm)?
  22. 22.What is ∛8? =
  23. 23.A big cube of edge 6 cm is cut into small cubes of edge 1 cm. How many small cubes are there?
  24. 24.What is ∛12167? =
  25. 25.Which of these is a perfect cube? (a) 485 (b) 382 (c) 343
  26. 26.A cube has a volume of 1331 cubic cm. How long is each edge (in cm)?
  27. 27.What is ∛15625? =
  28. 28.A big cube of edge 15 cm is cut into small cubes of edge 3 cm. How many small cubes are there?
  29. 29.A cube has a volume of 512 cubic cm. How long is each edge (in cm)?
  30. 30.Which of these is a perfect cube? (a) 512 (b) 514 (c) 585
  31. 31.What is the smallest whole number by which 576 must be divided to get a perfect cube?
  32. 32.A cube has a volume of 2197 cubic cm. How long is each edge (in cm)?
  33. 33.What is ∛729? =
  34. 34.What is the smallest whole number by which 256 must be multiplied to get a perfect cube?
  35. 35.What is the smallest whole number by which 108 must be multiplied to get a perfect cube?
  36. 36.A cube has a volume of 4096 cubic cm. How long is each edge (in cm)?
  37. 37.A big cube of edge 9 cm is cut into small cubes of edge 3 cm. How many small cubes are there?
  38. 38.What is the smallest whole number by which 1125 must be multiplied to get a perfect cube?
  39. 39.What is ∛125? =
  40. 40.A cube has a volume of 3375 cubic cm. How long is each edge (in cm)?

Answer key

  1. 125
  2. 27
  3. 2744
  4. 27
  5. 21
  6. 343
  7. 4
  8. 1331
  9. 15
  10. 125
  11. 1728
  12. 9
  13. 3
  14. 25
  15. 8
  16. 216
  17. 729
  18. 19
  19. 27
  20. 7
  21. 7
  22. 2
  23. 216
  24. 23
  25. 343
  26. 11
  27. 25
  28. 125
  29. 8
  30. 512
  31. 9
  32. 13
  33. 9
  34. 2
  35. 2
  36. 16
  37. 27
  38. 3
  39. 5
  40. 15

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