Year 6 - Maths
Explore mental and written strategies to solve problems
Rounding and solving problems with numbers up to 7 digits
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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 use their knowledge of the composition of seven-digit numbers to round them and to solve problems, adding and subtracting numbers whilst crossing the millions boundary.
Lesson Summary
You will learn to explore written and mental strategies to solve problems.
Key Notes
- Looking at the numbers involved and using number-sense supports us to know which strategy is more efficient.
- A number line is a useful mental strategy when it is obvious what to add or subtract.
- When using a formal written method the concept of constant difference can be used to make the calculation easier.
Vocabulary To Learn
- Difference: The difference is the result of subtracting one number from another. It is how much one number differs from another - represented by how far apart they are on a number line.
- Efficient: Being efficient means finding a way to solve a problem quickly whilst also maintaining accuracy.
Common Mistakes To Avoid
- Children may automatically use a formal written algorithm.
3 Quick Questions (With Answers)
1. Solve this in steps: explain the method from this lesson and why each step matters.
Looking at the numbers involved and using number-sense supports us to know which strategy is more efficient. A number line is a useful mental strategy when it is obvious what to add or subtract.
2. Use this key word in a maths sentence and explain it clearly. 'Difference'
The difference is the result of subtracting one number from another. It is how much one number differs from another - represented by how far apart they are on a number line. Use this word when showing your method, then check your final answer is reasonable.
3. Spot and fix this common maths mistake.
Mistake: Children may automatically use a formal written algorithm. Correction: What do you notice about the numbers? What would you add/subtract to get to the nearest multiple of (a power of 10)? Can you represent this on a number line?
More Lessons In This Unit
Browse all guides in the Year 6 Maths guide library.