Volume
Count the unit cubes in a solid drawn on the isometric grid, and draw a cuboid from the lengths given.
Your child learns that volume is a count of unit cubes. They count the cubes in a solid one layer at a time, hidden ones included, then find the volume of a cube or cuboid as the floor times the number of layers. They read and draw cuboids on isometric dot paper, change litres and millilitres to cubic centimetres, and work out what happens when water is poured between tanks. Read the study guide →
About this chapter
Primary 5 volume questions build solids with unit cubes, draw cubes and cuboids on an isometric grid, and find the volume of a cube or cuboid in cubic units. The chapter also finds the volume of liquid in a rectangular tank and links litres and millilitres with cm³.
Practise by question type: p5 volume of cube and cuboid questions, p5 isometric drawing questions, p5 unit cubes questions, p5 litres and cubic centimetres questions and p5 pouring between containers questions.
The order to learn them
Building, measuring and drawing solids
6.1 to 6.3
Count every unit cube, write the cubic unit, and use equal isometric steps when drawing a cube or cuboid.
What stays unchanged when the unit or container changes?
6.4 to 6.6
Keep the water volume fixed. Convert it to one unit, then use the new base area to find a level or missing measurement.
The number tells you where a question type sits in this chapter, not what your child needs to learn first. A child who has already met a type in school can practise it without working through the ones above it.
How the end-of-year papers set these questions
Volume appears throughout the Primary 5 papers.
The 2025 Primary 5 end-of-year papers include direct cube and cuboid calculations, solids built from unit cubes, liquid in tanks and water poured between containers.
Figures and units carry part of the question.
A short question may ask for one volume or conversion. Longer questions use a hidden cube, a fractional fill, a new water level or unequal base areas. The square and cubic units show what each line has found.
The questions are modelled against top school papers.
We used the 2025 Primary 5 end-of-year papers to check the question types and the written working. Every practice question is original, and no school question is reproduced.
Everything here is modelled against top school papers. Those papers are never reproduced, and every question on this site is original.
How to set out the working clearly
These examples show Mathweave's clear, consistent layout for each method. The layout is informed by the answer keys we reviewed.
- Mathweave writes the volume rule before substituting Mathweave writes volume = length × breadth × height before substituting measurements. This is our teaching layout; reviewed keys usually begin with the numerical calculation.
- Show hidden cubes and hidden edges clearly Count cubes that are hidden behind visible ones. On an isometric drawing, count equal grid steps from one vertex to the next and draw hidden edges with dashed lines.
- Write a conversion before using the converted value Litres, millilitres and cubic centimetres are linked by a line of equals. Keep the conversion line visible before the converted volume is used in another calculation.
- Name the base area before finding a water level Water keeps the same volume when it is poured into another container. Write the new base area on its own line, then divide the water volume by that area to find the level.
Questions parents ask
Is this the Primary 5 syllabus?
The chapter follows the latest MOE Primary Mathematics syllabus. It covers unit cubes, cubic units, isometric drawings, cube and cuboid volume, liquid in tanks and the relationship between litres, millilitres and cubic centimetres.
Why do five lesson pages say Primary 5 and Primary 6?
Building with unit cubes, cuboid volume, water level, unit conversion and pouring between containers are shared types. Each has one lesson page with the level line Primary 5 and Primary 6.
What does isometric drawing practice teach?
It teaches children to count equal grid steps from one vertex to the next and draw hidden edges with dashed lines.
Are the questions from past papers?
We write the questions ourselves rather than copy them from papers. Each chapter is modelled on the types of question that top school papers set. A question may look like one your child has met before because it is the same type.
Primary 5 volume questions by question type
Primary 5 Volume Study Guide
Lift the layers off a solid to find its hidden cube, stack floors of squares into a cuboid, and count the steps along a cuboid on dot paper. Five steps to tap through, worked examples and a five-question check.
Start hereUnit cubesCube and cuboidIsometric gridLitres and cm³TanksOpen the study guide →