Year 6 - Maths
Explain how adjusting the minuend can make mental calculation easier
Use equivalence and compensation to simplify and solve subtraction problems
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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 will explain how increasing or decreasing the minuend affects the difference and solve subtraction calculations mentally by using known facts explaining how adjusting the minuend can make mental calculation easier.
Lesson Summary
You will learn to explain how adjusting the minuend can make mental calculation easier.
Key Notes
- If you increase the minuend the difference increases by the same amount.
- If you decrease the minuend the difference decreases by the same amount.
- Partitioning the minuend can simplify the calculation.
Vocabulary To Learn
- Minuend: The minuend is the number being subtracted from.
- Subtrahend: A subtrahend is a number subtracted from another.
- Adjust: When you adjust you make a change to a number. This is done to make a calculation easier to solve mentally.
- Inverse: The inverse is the opposite or reverse operation. For example, subtraction is the inverse operation of addition.
Common Mistakes To Avoid
- Pupils may be eager to use columnar written methods for larger integers and decimals instead of considering the values and using an efficient strategy.
3 Quick Questions (With Answers)
1. Solve this in steps: explain the method from this lesson and why each step matters.
If you increase the minuend the difference increases by the same amount. If you decrease the minuend the difference decreases by the same amount.
2. Use this key word in a maths sentence and explain it clearly. 'Minuend'
The minuend is the number being subtracted from. Use this word when showing your method, then check your final answer is reasonable.
3. Spot and fix this common maths mistake.
Mistake: Pupils may be eager to use columnar written methods for larger integers and decimals instead of considering the values and using an efficient strategy. Correction: Emphasise the importance of trying different mental methods so that pupils aren't reliant on written methods that prevent them from fully grasping the underlying structure of additive problems.
More Lessons In This Unit
- Calculate the difference using knowledge of an adjusted subtrahend: difference structure Study Guide
- Explain and represent constant difference for subtraction Study Guide
- Explain how adjusting the subtrahend affects the difference: partitioning Study Guide
- Explain how adjusting the subtrahend affects the difference: reduction structure Study Guide
- Explain how constant difference can make written calculations more efficient Study Guide
- Explain how increasing or decreasing the minuend affects the difference Study Guide
- Solve subtraction calculations mentally by using known facts Study Guide
- Use constant difference to balance equations and find unknowns Study Guide
- Use equivalence and compensation strategies to solve subtraction problems in a range of contexts Study Guide
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