Year 5 - Maths
Multiply a 3-digit by a 1-digit number with no regroups
Multiplication by partitioning leading to short multiplication (3 by 1-digit)
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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 multiply a 3-digit number by a single-digit number using expanded and short multiplication.
Lesson Summary
You will learn to multiply a 3-digit by a 1-digit number using expanded and short multiplication (no regroups).
Key Notes
- Expanded multiplication of a 3-digit by a 1-digit number will give three numbers to add to calculate the overall product
- Short multiplication builds the overall product from the ones column to the hundreds with no regrouping.
- The partial products can be seen in the expanded and short multiplication strategies.
Vocabulary To Learn
- Expanded multiplication: A way of recording the steps of a calculation focusing on partitioning one or more factors and showing partial products.
- Short multiplication: A way of recording using columns to set out and calculate a multiplication.
- Factors: Numbers we can multiply together to get another number.
Common Mistakes To Avoid
- Misalignment of digits when setting out short multiplication.
3 Quick Questions (With Answers)
1. Solve this in steps: explain the method from this lesson and why each step matters.
Expanded multiplication of a 3-digit by a 1-digit number will give three numbers to add to calculate the overall product. Short multiplication builds the overall product from the ones column to the hundreds with no regrouping.
2. Use this key word in a maths sentence and explain it clearly. 'Expanded multiplication'
A way of recording the steps of a calculation focusing on partitioning one or more factors and showing partial products. Use this word when showing your method, then check your final answer is reasonable.
3. Spot and fix this common maths mistake.
Mistake: Misalignment of digits when setting out short multiplication. Correction: Clear teacher modelling, ask pupils 'what does this digit represent?' Return to expanded layout briefly, before re-doing the problem.
More Lessons In This Unit
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