Year 4 - Maths
Pupils use strategies to make solving calculations more efficient
Column addition and subtraction with 4-digit numbers
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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 consolidate column addition with regrouping and column subtraction with exchanging to solve problems. They will use known facts and strategies to accurately and efficiently calculate and check.
Lesson Summary
You will learn to use strategies to make solving calculations more efficient.
Key Notes
- Equivalent calculations can be used with the same difference or same sum to make calculations 'easier'.
- A number line can be used to represent more efficient methods.
- Inverse, the relationship between addition and subtraction, can be used to solve missing number problems.
Vocabulary To Learn
- Efficient: Working efficiently means finding a way to solve a problem quickly whilst also maintaining accuracy.
- Equivalent: Two or more things have the same value.
- Inverse: The opposite in effect. The reverse of.
Common Mistakes To Avoid
- When using adjustment (e.g. 456 − 199), pupils may forget to subtract or add 1 to both parts.
3 Quick Questions (With Answers)
1. Solve this in steps: explain the method from this lesson and why each step matters.
Equivalent calculations can be used with the same difference or same sum to make calculations 'easier'. A number line can be used to represent more efficient methods.
2. Use this key word in a maths sentence and explain it clearly. 'Efficient'
Working efficiently means finding a way to solve a problem quickly whilst also maintaining accuracy. Use this word when showing your method, then check your final answer is reasonable.
3. Spot and fix this common maths mistake.
Mistake: When using adjustment (e.g. 456 − 199), pupils may forget to subtract or add 1 to both parts. Correction: The emphasis of same difference can encourage children to ensure they have subtracted or added to both parts of the calculation. Clearly display the visuals in this lesson to support with this.
More Lessons In This Unit
Browse all guides in the Year 4 Maths guide library.