← Cubes and cube roots lesson New set →

Class 8 Maths Worksheet: Cubes and Cube Roots

Maths worksheets lesson 59: Cubes and cube roots · Set 935 · 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.What is ∛729? =
  2. 2.What is ∛9261? =
  3. 3.A big cube of edge 9 cm is cut into small cubes of edge 3 cm. How many small cubes are there?
  4. 4.What is the smallest whole number by which 320 must be multiplied to get a perfect cube?
  5. 5.Which of these is a perfect cube? (a) 1528 (b) 1331 (c) 1405
  6. 6.What is the smallest whole number by which 1080 must be multiplied to get a perfect cube?
  7. 7.What is 12³? =
  8. 8.A big cube of edge 12 cm is cut into small cubes of edge 4 cm. How many small cubes are there?
  9. 9.A big cube of edge 18 cm is cut into small cubes of edge 3 cm. How many small cubes are there?
  10. 10.What is the smallest whole number by which 24 must be divided to get a perfect cube?
  11. 11.A cube has a volume of 4096 cubic cm. How long is each edge (in cm)?
  12. 12.A big cube of edge 6 cm is cut into small cubes of edge 3 cm. How many small cubes are there?
  13. 13.Which of these is a perfect cube? (a) 89 (b) 64 (c) 103
  14. 14.What is the smallest whole number by which 16 must be multiplied to get a perfect cube?
  15. 15.A big cube of edge 12 cm is cut into small cubes of edge 3 cm. How many small cubes are there?
  16. 16.A big cube of edge 6 cm is cut into small cubes of edge 2 cm. How many small cubes are there?
  17. 17.What is 15³? =
  18. 18.A big cube of edge 16 cm is cut into small cubes of edge 4 cm. How many small cubes are there?
  19. 19.Which of these is a perfect cube? (a) 3375 (b) 3772 (c) 3484
  20. 20.Which of these is a perfect cube? (a) 615 (b) 512 (c) 632
  21. 21.What is the smallest whole number by which 16 must be divided to get a perfect cube?
  22. 22.A big cube of edge 2 cm is cut into small cubes of edge 1 cm. How many small cubes are there?
  23. 23.Which of these is a perfect cube? (a) 292 (b) 225 (c) 216
  24. 24.A big cube of edge 10 cm is cut into small cubes of edge 2 cm. How many small cubes are there?
  25. 25.What is 18³? =
  26. 26.What is ∛15625? =
  27. 27.What is ∛8? =
  28. 28.What is the smallest whole number by which 375 must be multiplied to get a perfect cube?
  29. 29.What is ∛1331? =
  30. 30.What is 2³? =
  31. 31.A cube has a volume of 3375 cubic cm. How long is each edge (in cm)?
  32. 32.A cube has a volume of 8 cubic cm. How long is each edge (in cm)?
  33. 33.A big cube of edge 20 cm is cut into small cubes of edge 4 cm. How many small cubes are there?
  34. 34.What is the smallest whole number by which 200 must be multiplied to get a perfect cube?
  35. 35.A cube has a volume of 125 cubic cm. How long is each edge (in cm)?
  36. 36.What is ∛2744? =
  37. 37.What is ∛216? =
  38. 38.What is 6³? =
  39. 39.Which of these is a perfect cube? (a) 2522 (b) 2197 (c) 2367
  40. 40.A big cube of edge 12 cm is cut into small cubes of edge 2 cm. How many small cubes are there?

Answer key

  1. 9
  2. 21
  3. 27
  4. 25
  5. 1331
  6. 25
  7. 1728
  8. 27
  9. 216
  10. 3
  11. 16
  12. 8
  13. 64
  14. 4
  15. 64
  16. 27
  17. 3375
  18. 64
  19. 3375
  20. 512
  21. 2
  22. 8
  23. 216
  24. 125
  25. 5832
  26. 25
  27. 2
  28. 9
  29. 11
  30. 8
  31. 15
  32. 2
  33. 125
  34. 5
  35. 5
  36. 14
  37. 6
  38. 216
  39. 2197
  40. 216

Free maths worksheets lessons, practice and worksheets at talentjr.in/maths-worksheets