Year 1 - Maths
Show one more and one less than a number using representations
Composition of numbers 0 to 5
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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 revisit how numbers are represented cardinally and ordinally. They will partition 1 - 5 in different ways, find a missing part when one part and the whole are known and explore one more and one less with numbers to five.
Lesson Summary
You will learn to use representations to show that the number before a given number is one less and the number after a given number is one more.
Key Notes
- The number before a given number is one less than it.
- The number after a given number is one more than it.
- A staircase of blocks can be used to highlight one more and one less.
Vocabulary To Learn
- One more: The number after a given number is one more than it.
- One less: The number before a given number is one less than it.
- Before: A number that is before another comes earlier in our count.
- After: A number that is after another comes later in our count.
Common Mistakes To Avoid
- Children may confuse one more and one less, particularly when finding missing numbers.
3 Quick Questions (With Answers)
1. Solve this in steps: explain the method from this lesson and why each step matters.
The number before a given number is one less than it. The number after a given number is one more than it.
2. Use this key word in a maths sentence and explain it clearly. 'One more'
The number after a given number is one more than it. 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 confuse one more and one less, particularly when finding missing numbers. Correction: Use the stem sentence ___ is one more / one less than ___ because it comes after / before it in our count.
More Lessons In This Unit
- Explain that numbers can represent how many objects there are in a set Study Guide
- Find a missing part when one part and the whole is known Study Guide
- Ordinal numbers show the position of an object in relation to another Study Guide
- Partition numbers one to five in different ways Study Guide
- Partition the numbers one to five in a systematic way Study Guide
- Show one more and one less than a number using representations and describe this accurately Study Guide
- Solve problems finding a missing part when one part and the whole is known Study Guide
- Solve problems using a bar model to represent a whole partitioned into two parts Study Guide
- Use a bar model to represent a whole partitioned into two parts Study Guide
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