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Grade 8 · Math · Unit 8 of 10

Surface Area & Volume

Prisms, cylinders, nets and views

What your child practises

Finding surface area and volume of boxes, cubes, triangular prisms and cylinders, working backwards to a missing dimension, linking cm³ to millilitres, and recognizing nets and views of 3D objects.

New Brunswick Curriculum skill descriptor: Shape and Space: Measurement · surface area and volume of prisms and cylinders

How we explain it

Children can open this short lesson before they practise.

  1. Surface area is the area of all the faces added up.
  2. Volume of a cylinder: V = π × r² × h.
  3. Use π ≈ 3.14.

Example: A cylinder has radius 3 cm and height 5 cm. What is its volume? r² = 3 × 3 = 9. V ≈ 3.14 × 9 × 5 = 141.3. Answer: About 141.3 cm³

Sample questions

A taste of this unit. In the app, questions change every time and get easier or harder to match your child.

  1. Question 1

    A box is 3 cm long, 5 cm wide and 9 cm tall. What is its surface area?

    answer boxcm²

  2. Question 2

    A cube has edges of 6 cm. What is its surface area?

    answer boxcm²

  3. Question 3

    A triangular prism has a triangle base of 14 cm and height 9 cm. The prism is 4 cm long. What is its volume?

    answer boxcm³

  4. Question 4

    A cylinder has a radius of 4 cm and a height of 20 cm. What is its volume? Use π ≈ 3.14 and round to 1 decimal place.

    answer boxcm³

  5. Question 5

    What is the surface area of a closed cylinder with radius 2 cm and height 15 cm? Use π ≈ 3.14 and round to 1 decimal place.

    answer boxcm²

  6. Question 6

    A box with a volume of 60 cm³ is 2 cm long and 10 cm wide. How tall is it?

    answer boxcm

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