← Cubes and cube roots lesson New set →

Class 8 Maths Worksheet: Cubes and Cube Roots

Maths worksheets lesson 59: Cubes and cube roots · Set 454 · 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 the smallest whole number by which 10584 must be divided to get a perfect cube?
  2. 2.What is the smallest whole number by which 128 must be divided to get a perfect cube?
  3. 3.Which of these is a perfect cube? (a) 1559 (b) 1380 (c) 1331
  4. 4.A cube has a volume of 216 cubic cm. How long is each edge (in cm)?
  5. 5.What is 10³? =
  6. 6.A cube has a volume of 8000 cubic cm. How long is each edge (in cm)?
  7. 7.What is ∛1728? =
  8. 8.A cube has a volume of 1728 cubic cm. How long is each edge (in cm)?
  9. 9.A big cube of edge 8 cm is cut into small cubes of edge 4 cm. How many small cubes are there?
  10. 10.A big cube of edge 4 cm is cut into small cubes of edge 1 cm. How many small cubes are there?
  11. 11.Which of these is a perfect cube? (a) 2744 (b) 2921 (c) 3050
  12. 12.A big cube of edge 8 cm is cut into small cubes of edge 2 cm. How many small cubes are there?
  13. 13.A cube has a volume of 512 cubic cm. How long is each edge (in cm)?
  14. 14.A big cube of edge 18 cm is cut into small cubes of edge 3 cm. How many small cubes are there?
  15. 15.A big cube of edge 6 cm is cut into small cubes of edge 2 cm. How many small cubes are there?
  16. 16.What is 12³? =
  17. 17.A cube has a volume of 3375 cubic cm. How long is each edge (in cm)?
  18. 18.A big cube of edge 24 cm is cut into small cubes of edge 4 cm. How many small cubes are there?
  19. 19.What is 17³? =
  20. 20.A cube has a volume of 4096 cubic cm. How long is each edge (in cm)?
  21. 21.A cube has a volume of 343 cubic cm. How long is each edge (in cm)?
  22. 22.A big cube of edge 4 cm is cut into small cubes of edge 2 cm. How many small cubes are there?
  23. 23.A big cube of edge 10 cm is cut into small cubes of edge 2 cm. How many small cubes are there?
  24. 24.What is ∛5832? =
  25. 25.What is ∛15625? =
  26. 26.What is 6³? =
  27. 27.A big cube of edge 3 cm is cut into small cubes of edge 1 cm. How many small cubes are there?
  28. 28.What is the smallest whole number by which 375 must be multiplied to get a perfect cube?
  29. 29.A big cube of edge 6 cm is cut into small cubes of edge 3 cm. How many small cubes are there?
  30. 30.Which of these is a perfect cube? (a) 2341 (b) 2197 (c) 2627
  31. 31.Which of these is a perfect cube? (a) 306 (b) 216 (c) 222
  32. 32.What is the smallest whole number by which 189 must be divided to get a perfect cube?
  33. 33.What is ∛3375? =
  34. 34.A cube has a volume of 125 cubic cm. How long is each edge (in cm)?
  35. 35.Which of these is a perfect cube? (a) 364 (b) 355 (c) 343
  36. 36.What is the smallest whole number by which 24 must be divided to get a perfect cube?
  37. 37.A cube has a volume of 5832 cubic cm. How long is each edge (in cm)?
  38. 38.A big cube of edge 9 cm is cut into small cubes of edge 3 cm. How many small cubes are there?
  39. 39.What is the smallest whole number by which 9 must be divided to get a perfect cube?
  40. 40.What is ∛125? =

Answer key

  1. 49
  2. 2
  3. 1331
  4. 6
  5. 1000
  6. 20
  7. 12
  8. 12
  9. 8
  10. 64
  11. 2744
  12. 64
  13. 8
  14. 216
  15. 27
  16. 1728
  17. 15
  18. 216
  19. 4913
  20. 16
  21. 7
  22. 8
  23. 125
  24. 18
  25. 25
  26. 216
  27. 27
  28. 9
  29. 8
  30. 2197
  31. 216
  32. 7
  33. 15
  34. 5
  35. 343
  36. 3
  37. 18
  38. 27
  39. 9
  40. 5

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