Year 2 - Maths
Explain different strategies used to subtract
Addition and subtraction of two 2-digit numbers
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Study Guides
This pupil-friendly study guide includes a unit summary, clear notes, common mistakes, and quick questions with answers.
Unit Summary
In this unit pupils apply their knowledge of known facts and understanding of place value to add and subtract with 2-digit numbers both within and across the tens boundary.
Lesson Summary
You will learn to explain different strategies used to subtract.
Key Notes
- Known strategies can be used to help subtract two 2-digit numbers efficiently.
- It is important to be able to calculate mentally when beginning to subtract two 2-digit numbers.
Vocabulary To Learn
- Calculate: To work out an answer, often by adding or subtracting.
- Efficiently: Not wasting time or effort. An efficient strategy is one we can carry out easily.
Common Mistakes To Avoid
- Children do not always make the link to prior learning automatically, so when new numbers are introduced, they can sometimes revert to inefficient strategies.
3 Quick Questions (With Answers)
1. Solve this in steps: explain the method from this lesson and why each step matters.
Known strategies can be used to help subtract two 2-digit numbers efficiently. It is important to be able to calculate mentally when beginning to subtract two 2-digit numbers.
2. Use this key word in a maths sentence and explain it clearly. 'Calculate'
To work out an answer, often by adding or subtracting. Use this word when showing your method, then check your final answer is reasonable.
3. Spot and fix this common maths mistake.
Mistake: Children do not always make the link to prior learning automatically, so when new numbers are introduced, they can sometimes revert to inefficient strategies. Correction: It is important that the use of efficient strategies that are already known are focused upon when equations with new numbers are introduced so that prior knowledge can be used to support new learning and children can continue to work efficiently.
More Lessons In This Unit
- Add 2-digit numbers when crossing the tens boundary Study Guide
- Add two-digit numbers without crossing the tens boundary Study Guide
- Combine tens and ones within equations Study Guide
- Create addition and subtraction problems Study Guide
- Find the missing addend when adding two-digit numbers Study Guide
- Find the missing part when subtracting two-digit numbers Study Guide
- Solve equations involving the subtraction of two-digit numbers Study Guide
- Solve problems involving addition and subtraction Study Guide
- Solve problems involving subtraction of two-digit numbers Study Guide
- Solve problems involving subtraction when bridging 10 Study Guide
- Solve problems involving the addition of two-digit numbers Study Guide
- Subtract two-digit numbers crossing the tens boundary Study Guide
- Use efficient addition strategies to calculate Study Guide
- Use efficient methods to solve subtraction equations Study Guide
Browse all guides in the Year 2 Maths guide library.