Year 3 - Maths
Use known facts to add and subtract multiples of 100 within 1000
Representing 3-digit numbers, comparing and positioning on number lines
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 use knowledge of place value to represent a 3-digit number in different ways. They will compare and order 3-digit numbers and position on number lines and unmarked number lines.
Lesson Summary
You will learn to add and subtract multiples of 100.
Key Notes
- Known facts can be used to help calculate with multiples of a hundred.
- If we know that 2 ones plus 4 ones equals 6 ones we know that 2 100s plus 4 100s equals 6 100s.
- Number facts to 10 can help us to add and subtract multiples of a hundred.
Vocabulary To Learn
- Known facts: A known fact is something that you already know and can use to help you.
- Multiple: A multiple is the result of multiplying a number by another whole number.
Common Mistakes To Avoid
- Pupils may find it difficult to connect calculating with hundreds with known facts.
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 calculate with multiples of a hundred. If we know that 2 ones plus 4 ones equals 6 ones we know that 2 100s plus 4 100s equals 6 100s.
2. Use this key word in a maths sentence and explain it clearly. 'Known facts'
A known fact is something that you already know and can use to help you. Use this word when showing your method, then check your final answer is reasonable.
3. Spot and fix this common maths mistake.
Mistake: Pupils may find it difficult to connect calculating with hundreds with known facts. Correction: Pupils need to be encouraged to 'unitise' hundreds to make calculation easier, seeing 500 as 5 lots of one hundred.
More Lessons In This Unit
- Add and subtract to and from a 3-digit number bridging 100 Study Guide
- Comparing and ordering numbers with 1, 2 and 3 digits Study Guide
- Count forwards and backwards in multiples of 2, 20, 5, 50 and 25 Study Guide
- Count forwards and backwards within 3-digits Study Guide
- Estimate the position of 3-digit numbers on unmarked number lines Study Guide
- Ordering sets of 3-digit numbers Study Guide
- Partition 3-digit numbers in different ways Study Guide
- Position 3-digit numbers on number lines Study Guide
- Represent a 3-digit number up to 1,000 in different ways Study Guide
- Solve problems by adding and subtracting to or from 3-digit numbers Study Guide
- Solve problems by counting forwards and backwards in multiples of 2, 20, 5, 50 and 25 Study Guide
- Use known facts to add and subtract to and from multiples of 100 Study Guide
- Use known facts to solve problems involving partitioning numbers Study Guide
- Write a 3-digit multiple of 10 as a multiplication equation Study Guide
Browse all guides in the Year 3 Maths guide library.