Year 2 - Maths
Represent addition and subtraction of tens and ones with equations
Comparing, ordering and partitioning 2-digit numbers
Study Hub
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 compare two 2-digit numbers and partition a 2-digit number into 10s and 1s and position on a number line.
Lesson Summary
You will learn to represent the combining and partitioning of tens and ones with addition and subtraction equations.
Key Notes
- When tens and ones are combined to make a two-digit number, this can be represented it as an addition equation.
- When a two-digit number is partitioned into tens and ones, this can be represented as a subtraction equation.
Vocabulary To Learn
- Partition: To split a whole up into parts.
- Combine: To put parts together to make a whole.
- Part: A piece or section of a whole.
- Whole: All of something; complete.
Common Mistakes To Avoid
- Children may fail to appreciate the importance of the equals sign in an equation, e.g. making errors such as 16 = 4 + 20, or confuse the value of the digits, making errors such as 43 = 4 + 30
3 Quick Questions (With Answers)
1. Solve this in steps: explain the method from this lesson and why each step matters.
When tens and ones are combined to make a two-digit number, this can be represented it as an addition equation. When a two-digit number is partitioned into tens and ones, this can be represented as a subtraction equation.
2. Use this key word in a maths sentence and explain it clearly. 'Partition'
To split a whole up into parts. 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 fail to appreciate the importance of the equals sign in an equation, e.g. making errors such as 16 = 4 + 20, or confuse the value of the digits, making errors such as 43 = 4 + 30. Correction: Use the language of parts and whole to activate/link to prior learning. Encourage drawing of own part-part-whole models. Encourage children to spot errors and explain why they are are incorrect and to articulate their thinking around correct answers.
More Lessons In This Unit
Browse all guides in the Year 2 Maths guide library.