Year 5 - Maths
Explain that different lengths can be composed additively and multiplicatively
Use knowledge of decimals to solve problems in different contexts: length
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This pupil-friendly study guide includes a unit summary, clear notes, common mistakes, and quick questions with answers.
Unit Summary
In this unit pupils will use their knowledge of decimal place value to convert between and compare metres and centimetres explaining that different lengths can be composed additively and multiplicatively.
Lesson Summary
You will learn to explain that different lengths can be represented as addition and multiplication.
Key Notes
- Partitioning 100 in different ways can be used to compose lengths.
- There are four 25s in 100 so there are four 25cm lengths in 1m.
- 1m divided into four equal parts is 25cm or 0.25m.
- 1m divided into five equal parts is 20cm or 0.2m.
Vocabulary To Learn
- Common: Something is common when it is frequently used or it occurs regularly.
- Compose: Larger numbers can be composed of smaller numbers.
- Partition: The act of splitting an object or value down into smaller parts.
Common Mistakes To Avoid
- Pupils think that when a whole is divided into x parts, they need to have x interval markers.
3 Quick Questions (With Answers)
1. Solve this in steps: explain the method from this lesson and why each step matters.
Partitioning 100 in different ways can be used to compose lengths. There are four 25s in 100 so there are four 25cm lengths in 1m.
2. Use this key word in a maths sentence and explain it clearly. 'Common'
Something is common when it is frequently used or it occurs regularly. Use this word when showing your method, then check your final answer is reasonable.
3. Spot and fix this common maths mistake.
Mistake: Pupils think that when a whole is divided into x parts, they need to have x interval markers. Correction: Encourage pupils to make connections between the bar model and the number line, drawing attention to where each whole has been divided.
More Lessons In This Unit
- Compare and order numbers with up to 3 decimal places Study Guide
- Read and write numbers with up to 3 decimal places Study Guide
- Round a decimal number with hundredths to the nearest tenth Study Guide
- Round a decimal number with hundredths to the nearest whole number Study Guide
- Solve problems with numbers with up to 3 decimal places Study Guide
- Use knowledge of column addition and subtraction to calculate with decimals: tenths and hundredths Study Guide
- Use knowledge of decimal place value to convert between and compare metres and centimetres Study Guide
- Use knowledge of decimal place value to solve problems in different contexts Study Guide
- Use knowledge of place value to calculate with decimal numbers up to and bridging one tenth Study Guide
Browse all guides in the Year 5 Maths guide library.