← Cubes and cube roots lesson New set →

Class 8 Maths Worksheet: Cubes and Cube Roots

Maths worksheets lesson 59: Cubes and cube roots · Set 89 · 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 9³? =
  2. 2.What is 19³? =
  3. 3.What is the smallest whole number by which 7 must be multiplied to get a perfect cube?
  4. 4.What is 3³? =
  5. 5.A cube has a volume of 1331 cubic cm. How long is each edge (in cm)?
  6. 6.What is the smallest whole number by which 9 must be multiplied to get a perfect cube?
  7. 7.Which of these is a perfect cube? (a) 34 (b) 35 (c) 27
  8. 8.What is the smallest whole number by which 448 must be divided to get a perfect cube?
  9. 9.What is the smallest whole number by which 5 must be multiplied to get a perfect cube?
  10. 10.What is 12³? =
  11. 11.A cube has a volume of 8 cubic cm. How long is each edge (in cm)?
  12. 12.What is ∛5832? =
  13. 13.What is the smallest whole number by which 250 must be multiplied to get a perfect cube?
  14. 14.A cube has a volume of 6859 cubic cm. How long is each edge (in cm)?
  15. 15.A big cube of edge 9 cm is cut into small cubes of edge 3 cm. How many small cubes are there?
  16. 16.What is ∛15625? =
  17. 17.What is ∛3375? =
  18. 18.A big cube of edge 10 cm is cut into small cubes of edge 2 cm. How many small cubes are there?
  19. 19.A cube has a volume of 729 cubic cm. How long is each edge (in cm)?
  20. 20.What is ∛729? =
  21. 21.Which of these is a perfect cube? (a) 362 (b) 454 (c) 343
  22. 22.Which of these is a perfect cube? (a) 1447 (b) 1515 (c) 1331
  23. 23.What is the smallest whole number by which 648 must be divided to get a perfect cube?
  24. 24.A cube has a volume of 216 cubic cm. How long is each edge (in cm)?
  25. 25.What is the smallest whole number by which 864 must be multiplied to get a perfect cube?
  26. 26.What is the smallest whole number by which 49 must be multiplied to get a perfect cube?
  27. 27.What is ∛2744? =
  28. 28.A big cube of edge 2 cm is cut into small cubes of edge 1 cm. How many small cubes are there?
  29. 29.Which of these is a perfect cube? (a) 3375 (b) 3762 (c) 3460
  30. 30.What is 6³? =
  31. 31.What is ∛1000? =
  32. 32.What is ∛512? =
  33. 33.What is ∛4096? =
  34. 34.Which of these is a perfect cube? (a) 1000 (b) 1147 (c) 1294
  35. 35.What is 11³? =
  36. 36.Which of these is a perfect cube? (a) 2744 (b) 3180 (c) 3072
  37. 37.What is 4³? =
  38. 38.What is ∛1331? =
  39. 39.A big cube of edge 4 cm is cut into small cubes of edge 2 cm. How many small cubes are there?
  40. 40.Which of these is a perfect cube? (a) 79 (b) 64 (c) 96

Answer key

  1. 729
  2. 6859
  3. 49
  4. 27
  5. 11
  6. 3
  7. 27
  8. 7
  9. 25
  10. 1728
  11. 2
  12. 18
  13. 4
  14. 19
  15. 27
  16. 25
  17. 15
  18. 125
  19. 9
  20. 9
  21. 343
  22. 1331
  23. 3
  24. 6
  25. 2
  26. 7
  27. 14
  28. 8
  29. 3375
  30. 216
  31. 10
  32. 8
  33. 16
  34. 1000
  35. 1331
  36. 2744
  37. 64
  38. 11
  39. 8
  40. 64

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