Year 2 - Maths
Use efficient strategies to solve problems
Adding and subtracting ones and tens to and from 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 will add and subtract 1s and 10s from 2 digit numbers. They will use number facts to add/subtract a single-digit number to/from a 2-digit number. They will use a part-part-whole model to represent addition and subtraction.
Lesson Summary
You will learn to use efficient strategies to solve addition and subtraction problems.
Key Notes
- Known facts can be used to help us solve equations and problems efficiently.
- Numbers can be partitioned to bridge ten to help us work efficiently.
- When equations are solved, it is important to choose a strategy that allows you to solve the problem efficiently.
Vocabulary To Learn
- Strategy: A method used to solve a problem or equation.
- Data: Another word for information.
- Bar chart: A graphical display of data using bars of different heights; another name for a bar graphs.
Common Mistakes To Avoid
- When faced with problems, children may revert to using inefficient counting strategies instead of more efficient calculation strategies.
3 Quick Questions (With Answers)
1. Solve this in steps: explain the method from this lesson and why each step matters.
Known facts can be used to help us solve equations and problems efficiently. Numbers can be partitioned to bridge ten to help us work efficiently.
2. Use this key word in a maths sentence and explain it clearly. 'Strategy'
A method used to solve a problem or equation. Use this word when showing your method, then check your final answer is reasonable.
3. Spot and fix this common maths mistake.
Mistake: When faced with problems, children may revert to using inefficient counting strategies instead of more efficient calculation strategies. Correction: Record equation required to solve a problem, then explicitly discuss the most efficient strategy to solve it, drawing on prior knowledge and strategies such as use of known facts and the bridge ten strategy.
More Lessons In This Unit
- Add and subtract 1 to and from a 2-digit number crossing the tens boundary Study Guide
- Add and subtract 10 to and from a 2-digit number. Study Guide
- Add and subtract one to or from a two-digit number within a decade Study Guide
- Add by bridging a multiple of ten Study Guide
- Add multiples of 10 to 2-digit numbers. Study Guide
- Find 10 more or less than a 2-digit number. Study Guide
- Partition 2-digit numbers in different ways Study Guide
- Subtract by bridging a multiple of ten Study Guide
- Subtract multiples of ten from 2-digit numbers Study Guide
- Use bridging to solve addition and subtraction problems Study Guide
- Use number bonds to 10 to add/subtract one-digit and two-digit numbers Study Guide
- Use number facts to add or subtract a one-digit number and a two-digit number. Study Guide
- Use number facts to solve addition and subtraction problems. Study Guide
- Use number facts to solve problems in measures and data contexts Study Guide
Browse all guides in the Year 2 Maths guide library.