Class 8 Maths Worksheet: Cubes and Cube Roots

Maths worksheets lesson 59: Cubes and cube roots · Set 78 · 40 sums

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.

1. 1.What is 20³? =
2. 2.What is ∛6859? =
3. 3.A cube has a volume of 64 cubic cm. How long is each edge (in cm)?
4. 4.Which of these is a perfect cube? (a) 41 (b) 35 (c) 27
5. 5.What is 3³? =
6. 6.Which of these is a perfect cube? (a) 923 (b) 900 (c) 729
7. 7.What is 9³? =
8. 8.A big cube of edge 15 cm is cut into small cubes of edge 3 cm. How many small cubes are there?
9. 9.What is the smallest whole number by which 3 must be multiplied to get a perfect cube?
10. 10.A cube has a volume of 8 cubic cm. How long is each edge (in cm)?
11. 11.What is ∛15625? =
12. 12.A big cube of edge 12 cm is cut into small cubes of edge 3 cm. How many small cubes are there?
13. 13.A cube has a volume of 216 cubic cm. How long is each edge (in cm)?
14. 14.What is 15³? =
15. 15.What is ∛216? =
16. 16.What is ∛2744? =
17. 17.What is the smallest whole number by which 375 must be multiplied to get a perfect cube?
18. 18.What is ∛343? =
19. 19.What is the smallest whole number by which 2 must be multiplied to get a perfect cube?
20. 20.What is the smallest whole number by which 16 must be multiplied to get a perfect cube?
21. 21.What is 5³? =
22. 22.Which of these is a perfect cube? (a) 266 (b) 282 (c) 216
23. 23.A cube has a volume of 4096 cubic cm. How long is each edge (in cm)?
24. 24.What is the smallest whole number by which 7 must be multiplied to get a perfect cube?
25. 25.A cube has a volume of 4913 cubic cm. How long is each edge (in cm)?
26. 26.What is ∛1331? =
27. 27.What is 6³? =
28. 28.What is 11³? =
29. 29.What is 7³? =
30. 30.Which of these is a perfect cube? (a) 1352 (b) 1331 (c) 1383
31. 31.A cube has a volume of 6859 cubic cm. How long is each edge (in cm)?
32. 32.A cube has a volume of 1728 cubic cm. How long is each edge (in cm)?
33. 33.What is ∛4096? =
34. 34.Which of these is a perfect cube? (a) 106 (b) 86 (c) 64
35. 35.A big cube of edge 16 cm is cut into small cubes of edge 4 cm. How many small cubes are there?
36. 36.What is ∛12167? =
37. 37.What is the smallest whole number by which 864 must be multiplied to get a perfect cube?
38. 38.A cube has a volume of 3375 cubic cm. How long is each edge (in cm)?
39. 39.What is the smallest whole number by which 3136 must be divided to get a perfect cube?
40. 40.What is 4³? =

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