Year 6 - Maths
Explain how to balance an equation with two unknowns
Solving problems with two unknowns
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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 compare and represent the structure of problems with two unknowns using a bar model. They will systematically solve problems with two unknowns using trial and improvement.
Lesson Summary
You will learn to explain how to balance an equation with two unknowns.
Key Notes
- The same sum rule can be used to balance equations.
- The same difference rule can be used to balance equations.
- Understanding of the structure of addition and subtraction can be used to balance equations.
Vocabulary To Learn
- Difference: The result of subtracting one number from another number is known as the difference.
- Subtrahend: The value used to subtract from the whole is known as the subtrahend.
Common Mistakes To Avoid
- Pupils use a trial and improvement approach to solve these problems only.
3 Quick Questions (With Answers)
1. Solve this in steps: explain the method from this lesson and why each step matters.
The same sum rule can be used to balance equations. The same difference rule can be used to balance equations.
2. Use this key word in a maths sentence and explain it clearly. 'Difference'
The result of subtracting one number from another number is known as the difference. Use this word when showing your method, then check your final answer is reasonable.
3. Spot and fix this common maths mistake.
Mistake: Pupils use a trial and improvement approach to solve these problems only. Correction: At first, pupils may put numbers into the equation to see what happens each time. Encourage pupils to move beyond this to notice what happens to each example. Pupils should aim to use the relationships between addends or subtrahends to help them.
More Lessons In This Unit
- Compare the structure of problems with one or two unknowns Study Guide
- Explain how to represent an equation with a bar model Study Guide
- Explain how you know you have found all the possible solutions to a problem with two unknowns Study Guide
- Explain why there is sometimes only one solution to a problem Study Guide
- Represent and solve problems with two unknowns efficiently Study Guide
- Represent the structure of a problem with two unknowns in context Study Guide
- Solve problems with two unknowns in a range of contexts Study Guide
- Solve problems with two unknowns with one, several and infinite solutions Study Guide
- Use a bar model to represent spatial problems with two unknowns Study Guide
Browse all guides in the Year 6 Maths guide library.