Units and Conversions
Units describe the size of a measurement, and conversions change a measurement from one unit to another using a conversion factor.
▶ Interact
Play with the controls to see the idea in action.
📘 Learn
Units describe the size of a measurement, and conversions change a measurement from one unit to another using a conversion factor.
- 1 metre equals 100 centimetres
- Area conversions use the square of the factor
- Always write the unit with your answer
🧠 Quick quiz
Three questions. Score 2 or more to complete the topic.
What is Units and Conversions?
Within Mathematics, which covers numbers, algebra, geometry, trigonometry and statistics from first principles to exam level, this topic explains Units and Conversions. Maths builds step by step, so each topic here gives you a rule, a picture and a quick check you can use on homework and in exams.
Check that you can explain Units and Conversions in your own words and give one example from everyday life. If you can do that, you have understood the core idea.
Understanding Units and Conversions gives you a reliable method you will reuse in later maths units, in science lessons and in data work.
Units and Conversions in detail
Units give measurements meaning, and converting between them uses the relationships such as 1 km = 1,000 m, 1 m = 100 cm, 1 kg = 1,000 g and 1 litre = 1,000 ml. To convert to a smaller unit, multiply, and to a larger unit, divide.
Take care with area and volume: 1 m² = 10,000 cm² and 1 m³ = 1,000,000 cm³, because you square or cube the length factor. Compound units such as km/h and m/s need two conversions. Accurate conversions matter in science, cooking, travel and international trade.
How the interactive helps you understand Units and Conversions
Click a step, or use the Previous and Next buttons, to move through the sequence one stage at a time. Auto-play moves on for you.
Before you change anything, predict the result. Then change one value at a time and check whether your prediction was right. This is a quick way to build a correct mental model of Units and Conversions.
Real-life uses and examples
- Use Units and Conversions when comparing prices, discounts or recipe quantities in everyday life.
- Explain Units and Conversions to a friend with a simple picture, such as a row of tiles or a bag of sweets.
- Spot Units and Conversions in exam questions, where it often sits inside a short word problem.
Common mistakes to avoid
- Forgetting units, signs or brackets when you apply Units and Conversions.
- Memorising the steps for Units and Conversions without checking why they work.
- Learning the definition without testing it. Use the quiz and the interactive to check that you can apply the idea.
Frequently asked questions about Units and Conversions
What is Units and Conversions?
Units describe the size of a measurement, and conversions change a measurement from one unit to another using a conversion factor.
What are the most important points about Units and Conversions?
The main points are: 1 metre equals 100 centimetres; Area conversions use the square of the factor; Always write the unit with your answer.
Why is Units and Conversions useful?
Understanding Units and Conversions gives you a reliable method you will reuse in later maths units, in science lessons and in data work.
How can I practise Units and Conversions?
Open the interactive at the top of this page and change the controls one at a time. Predict the result before each change, then take the three-question quiz. A score of two or more marks the topic as complete on this device.
Which topics are related to Units and Conversions?
Related topics in Mathematics include Vectors, Tree Diagrams and Combined Events, Mean, Median and Mode.