The volume of a cube and a cuboid is in the Primary 5 Volume chapter. The lesson film is the one Mathweave teaches this skill with in Primary 6, and the practice set below is written for Primary 5.
Lesson video, with the working
The volume of a cuboid
2 min 20 s
The film teaches 2 questions in turn. Each question shows first; its working is written as the film explains it.
A box has a length of 8 cm, a breadth of 5 cm and a height of 3 cm. Find the volume of the box.
volume = l × b × h
= 8 × 5 × 3
= 40 × 3
= 120 cm³
Ans: 120 cm³
Example 1
A solid is made from two rectangular boxes joined together, as shown. The lower box has a length of 10 cm, a breadth of 6 cm and a height of 4 cm. The upper box has a length of 5 cm, a breadth of 6 cm and a height of 3 cm. Find the volume of the solid.
volume = l × b × h
volume of lower box = 10 × 6 × 4 = 240 cm³
volume of upper box = 5 × 6 × 3 = 90 cm³
total volume of two boxes = 240 + 90 = 330 cm³
Ans: 330 cm³
How to solve it
Think of volume as layers one centimetre thick. One layer is the floor, the base area.
Count the floor: 8 squares along the front and 5 rows back, which is 8 times 5, or 40 squares.
Stack the floors: volume is length times breadth times height, so 40 times 3 is 120 cubic centimetres.
For two boxes joined, find each volume on its own. The lower box is 10 times 6 times 4, which is 240.
The upper box is 5 times 6 times 3, which is 90. Add them: 240 plus 90 is 330 cubic centimetres.
Two boxes joined are two volumes added. And the upper box is floors of squares too. Its floor is 5 by 6, and it is 3 floors high.
Practice questions with worked solutions
Question 1 is free to try. The other question opens in the free trial, each with its full working.
Question 1 of 2 · Basic · free to tryA room is 8 m long, 5 m broad and 3 m high. Find its volume in cubic metres.A room is 8 m long, 5 m broad…
A room is 8 m long, 5 m broad and 3 m high. Find its volume in cubic metres.
Show the working and the answer
Working
volume = length × breadth × height
= 8 × 5 × 3
= 40 × 3
= 120 m³
Answer: 120 m³
For parents
How do you solve P5 volume of cube and cuboid questions?
This page teaches the volume of a cube and a cuboid from the Primary 5 Area and Volume strand, measured in cubic units, cm³ or m³.
What your child learns here
This page teaches the volume of a cube and a cuboid from the Primary 5 Area and Volume strand, measured in cubic units, cm³ or m³. It goes on to solids made of cuboids joined together, where the volume of each part is found on its own.
The volume of a cuboid is the number of unit cubes that fill it.
Volume of a cuboid = length × breadth × height; for a cube it is edge × edge × edge.
Base area × height gives the same result: one layer of cubes, stacked up.
Volume is written in cubic units, such as cm³ or m³, not cm or cm².
A solid made of joined cuboids is split into cuboids, each volume is found, and the volumes are added.
Does the answer make sense?
Your child's volume answer must be in cubic units, cm³ or m³, never cm or cm². For a solid made of joined boxes, the total must be more than the biggest box on its own, because every other box adds to it.
How to practise these questions
The Challenge question joins several boxes, each worked out on its own, so your child must keep every length, breadth and height with its own box before the volumes are combined. If the volumes get mixed up, watch the solution film for that question, then try it again later from Revision.
Questions parents ask
What is the formula for the volume of a cuboid? Volume = length × breadth × height. For a cube every edge is the same, so it is edge × edge × edge.
Is volume of cube and cuboid in the Primary 5 syllabus? Yes. The Primary 5 Area and Volume strand includes building solids with unit cubes, measuring volume in cubic units, and the volume of a cube or cuboid.
Does my child need to convert between cm³ and m³? No. The Primary 5 syllabus measures volume in cm³ and m³ but leaves out conversion between them.
