← Cubes and cube roots lesson New set →

Class 8 Maths Worksheet: Cubes and Cube Roots

Maths worksheets lesson 59: Cubes and cube roots · Set 305 · 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 cube has a volume of 27 cubic cm. How long is each edge (in cm)?
  2. 2.A cube has a volume of 1728 cubic cm. How long is each edge (in cm)?
  3. 3.What is 14³? =
  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.A big cube of edge 10 cm is cut into small cubes of edge 2 cm. How many small cubes are there?
  6. 6.What is the smallest whole number by which 1125 must be multiplied to get a perfect cube?
  7. 7.What is ∛9261? =
  8. 8.What is the smallest whole number by which 128 must be multiplied to get a perfect cube?
  9. 9.What is the smallest whole number by which 16 must be multiplied to get a perfect cube?
  10. 10.What is 7³? =
  11. 11.What is ∛15625? =
  12. 12.A cube has a volume of 8 cubic cm. How long is each edge (in cm)?
  13. 13.What is 4³? =
  14. 14.What is the smallest whole number by which 32 must be divided to get a perfect cube?
  15. 15.What is ∛3375? =
  16. 16.What is 16³? =
  17. 17.Which of these is a perfect cube? (a) 321 (b) 324 (c) 216
  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.A cube has a volume of 125 cubic cm. How long is each edge (in cm)?
  20. 20.A big cube of edge 6 cm is cut into small cubes of edge 3 cm. How many small cubes are there?
  21. 21.What is ∛4913? =
  22. 22.What is ∛343? =
  23. 23.What is the smallest whole number by which 189 must be multiplied to get a perfect cube?
  24. 24.A cube has a volume of 3375 cubic cm. How long is each edge (in cm)?
  25. 25.Which of these is a perfect cube? (a) 1417 (b) 1331 (c) 1405
  26. 26.What is 15³? =
  27. 27.A cube has a volume of 2744 cubic cm. How long is each edge (in cm)?
  28. 28.What is the smallest whole number by which 4 must be multiplied to get a perfect cube?
  29. 29.What is ∛8000? =
  30. 30.What is ∛6859? =
  31. 31.A big cube of edge 24 cm is cut into small cubes of edge 4 cm. How many small cubes are there?
  32. 32.A big cube of edge 12 cm is cut into small cubes of edge 4 cm. How many small cubes are there?
  33. 33.What is ∛512? =
  34. 34.What is the smallest whole number by which 81 must be multiplied to get a perfect cube?
  35. 35.What is 12³? =
  36. 36.A cube has a volume of 1331 cubic cm. How long is each edge (in cm)?
  37. 37.Which of these is a perfect cube? (a) 2635 (b) 2197 (c) 2208
  38. 38.A big cube of edge 8 cm is cut into small cubes of edge 4 cm. How many small cubes are there?
  39. 39.Which of these is a perfect cube? (a) 1188 (b) 1164 (c) 1000
  40. 40.What is ∛2744? =

Answer key

  1. 3
  2. 12
  3. 2744
  4. 27
  5. 125
  6. 3
  7. 21
  8. 4
  9. 4
  10. 343
  11. 25
  12. 2
  13. 64
  14. 4
  15. 15
  16. 4096
  17. 216
  18. 64
  19. 5
  20. 8
  21. 17
  22. 7
  23. 49
  24. 15
  25. 1331
  26. 3375
  27. 14
  28. 2
  29. 20
  30. 19
  31. 216
  32. 27
  33. 8
  34. 9
  35. 1728
  36. 11
  37. 2197
  38. 8
  39. 1000
  40. 14

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