← Cubes and cube roots lesson New set →

Class 8 Maths Worksheet: Cubes and Cube Roots

Maths worksheets lesson 59: Cubes and cube roots · Set 39 · 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 ∛1331? =
  2. 2.A big cube of edge 6 cm is cut into small cubes of edge 1 cm. How many small cubes are there?
  3. 3.A cube has a volume of 4096 cubic cm. How long is each edge (in cm)?
  4. 4.A big cube of edge 6 cm is cut into small cubes of edge 2 cm. How many small cubes are there?
  5. 5.What is 19³? =
  6. 6.A cube has a volume of 3375 cubic cm. How long is each edge (in cm)?
  7. 7.Which of these is a perfect cube? (a) 1000 (b) 1061 (c) 1293
  8. 8.A big cube of edge 4 cm is cut into small cubes of edge 2 cm. How many small cubes are there?
  9. 9.What is the smallest whole number by which 448 must be divided to get a perfect cube?
  10. 10.What is ∛729? =
  11. 11.A cube has a volume of 216 cubic cm. How long is each edge (in cm)?
  12. 12.A big cube of edge 15 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) 125 (b) 135 (c) 189
  14. 14.What is ∛2744? =
  15. 15.What is the smallest whole number by which 81 must be multiplied to get a perfect cube?
  16. 16.What is ∛12167? =
  17. 17.What is 20³? =
  18. 18.Which of these is a perfect cube? (a) 696 (b) 512 (c) 676
  19. 19.A cube has a volume of 64 cubic cm. How long is each edge (in cm)?
  20. 20.What is 7³? =
  21. 21.What is ∛13824? =
  22. 22.What is 4³? =
  23. 23.What is the smallest whole number by which 72 must be divided to get a perfect cube?
  24. 24.A cube has a volume of 125 cubic cm. How long is each edge (in cm)?
  25. 25.What is the smallest whole number by which 5400 must be divided to get a perfect cube?
  26. 26.What is 11³? =
  27. 27.A big cube of edge 2 cm is cut into small cubes of edge 1 cm. How many small cubes are there?
  28. 28.What is 10³? =
  29. 29.What is ∛4913? =
  30. 30.A big cube of edge 8 cm is cut into small cubes of edge 4 cm. How many small cubes are there?
  31. 31.What is ∛64? =
  32. 32.A big cube of edge 18 cm is cut into small cubes of edge 3 cm. How many small cubes are there?
  33. 33.Which of these is a perfect cube? (a) 3221 (b) 2744 (c) 2831
  34. 34.Which of these is a perfect cube? (a) 1864 (b) 1728 (c) 1798
  35. 35.What is ∛9261? =
  36. 36.A cube has a volume of 6859 cubic cm. How long is each edge (in cm)?
  37. 37.What is the smallest whole number by which 108 must be multiplied to get a perfect cube?
  38. 38.What is the smallest whole number by which 625 must be multiplied to get a perfect cube?
  39. 39.Which of these is a perfect cube? (a) 37 (b) 28 (c) 27
  40. 40.What is the smallest whole number by which 243 must be divided to get a perfect cube?

Answer key

  1. 11
  2. 216
  3. 16
  4. 27
  5. 6859
  6. 15
  7. 1000
  8. 8
  9. 7
  10. 9
  11. 6
  12. 125
  13. 125
  14. 14
  15. 9
  16. 23
  17. 8000
  18. 512
  19. 4
  20. 343
  21. 24
  22. 64
  23. 9
  24. 5
  25. 25
  26. 1331
  27. 8
  28. 1000
  29. 17
  30. 8
  31. 4
  32. 216
  33. 2744
  34. 1728
  35. 21
  36. 19
  37. 2
  38. 25
  39. 27
  40. 9

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