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Class 8 Maths Worksheet: Cubes and Cube Roots

Maths worksheets lesson 59: Cubes and cube roots · Set 60 · 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.A big cube of edge 6 cm is cut into small cubes of edge 3 cm. How many small cubes are there?
  2. 2.What is the smallest whole number by which 25 must be multiplied to get a perfect cube?
  3. 3.A big cube of edge 10 cm is cut into small cubes of edge 2 cm. How many small cubes are there?
  4. 4.What is 12³? =
  5. 5.A big cube of edge 15 cm is cut into small cubes of edge 3 cm. How many small cubes are there?
  6. 6.What is ∛216? =
  7. 7.Which of these is a perfect cube? (a) 288 (b) 312 (c) 216
  8. 8.A big cube of edge 3 cm is cut into small cubes of edge 1 cm. How many small cubes are there?
  9. 9.What is 8³? =
  10. 10.A cube has a volume of 1000 cubic cm. How long is each edge (in cm)?
  11. 11.Which of these is a perfect cube? (a) 466 (b) 361 (c) 343
  12. 12.What is 16³? =
  13. 13.A cube has a volume of 6859 cubic cm. How long is each edge (in cm)?
  14. 14.A big cube of edge 12 cm is cut into small cubes of edge 4 cm. How many small cubes are there?
  15. 15.What is the smallest whole number by which 2 must be divided to get a perfect cube?
  16. 16.Which of these is a perfect cube? (a) 678 (b) 512 (c) 659
  17. 17.A cube has a volume of 27 cubic cm. How long is each edge (in cm)?
  18. 18.A cube has a volume of 1331 cubic cm. How long is each edge (in cm)?
  19. 19.What is ∛6859? =
  20. 20.A big cube of edge 5 cm is cut into small cubes of edge 1 cm. How many small cubes are there?
  21. 21.A cube has a volume of 343 cubic cm. How long is each edge (in cm)?
  22. 22.Which of these is a perfect cube? (a) 178 (b) 125 (c) 156
  23. 23.A big cube of edge 16 cm is cut into small cubes of edge 4 cm. How many small cubes are there?
  24. 24.Which of these is a perfect cube? (a) 1263 (b) 1000 (c) 1229
  25. 25.A cube has a volume of 125 cubic cm. How long is each edge (in cm)?
  26. 26.What is the smallest whole number by which 10584 must be multiplied to get a perfect cube?
  27. 27.What is ∛8000? =
  28. 28.Which of these is a perfect cube? (a) 1728 (b) 2059 (c) 1933
  29. 29.What is ∛1331? =
  30. 30.What is the smallest whole number by which 375 must be multiplied to get a perfect cube?
  31. 31.A cube has a volume of 3375 cubic cm. How long is each edge (in cm)?
  32. 32.What is the smallest whole number by which 189 must be multiplied to get a perfect cube?
  33. 33.What is ∛15625? =
  34. 34.What is ∛2197? =
  35. 35.What is 5³? =
  36. 36.What is the smallest whole number by which 135 must be multiplied to get a perfect cube?
  37. 37.A big cube of edge 24 cm is cut into small cubes of edge 4 cm. How many small cubes are there?
  38. 38.What is the smallest whole number by which 72 must be multiplied to get a perfect cube?
  39. 39.A big cube of edge 6 cm is cut into small cubes of edge 2 cm. How many small cubes are there?
  40. 40.What is ∛1000? =

Answer key

  1. 8
  2. 5
  3. 125
  4. 1728
  5. 125
  6. 6
  7. 216
  8. 27
  9. 512
  10. 10
  11. 343
  12. 4096
  13. 19
  14. 27
  15. 2
  16. 512
  17. 3
  18. 11
  19. 19
  20. 125
  21. 7
  22. 125
  23. 64
  24. 1000
  25. 5
  26. 7
  27. 20
  28. 1728
  29. 11
  30. 9
  31. 15
  32. 49
  33. 25
  34. 13
  35. 125
  36. 25
  37. 216
  38. 3
  39. 27
  40. 10

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