Year 5 - Maths
Multiply a 2-digit number by a 1-digit number using expanded multiplication (no regroups)
Multiplication by partitioning leading to short multiplication (2 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 2-digit number by a single-digit number using partitioning and representations using expanded multiplication and using short multiplication.
Lesson Summary
You will learn to represent partitioning in a column method for expanded multiplication.
Key Notes
- Knowledge of times tables and place value helps when multiplying 2-digit numbers.
- There are similarities between the representations of multiplication.
- Arranging the factors in columns allows you to organise the partial products into a column addition.
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.
- partial product: Any of the multiplication results that lead up to an overall multiplication result.
Common Mistakes To Avoid
- When using the expanded method, pupils may not align the digits correctly with the same place value.
3 Quick Questions (With Answers)
1. Solve this in steps: explain the method from this lesson and why each step matters.
Knowledge of times tables and place value helps when multiplying 2-digit numbers. There are similarities between the representations of multiplication.
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: When using the expanded method, pupils may not align the digits correctly with the same place value. Correction: Use clear teacher modelling and continue to ask what each digit that has been recorded represents and link back to the place value chart.
More Lessons In This Unit
- Estimate and multiply a 2-digit by a 1-digit number using expanded and short multiplication Study Guide
- Multiply a 2-digit number by a 1-digit number using expanded multiplication (regrouping 10s to 100s) Study Guide
- Multiply a 2-digit number by a 1-digit number using expanded multiplication (regrouping 1s to 10s) Study Guide
- Multiply a 2-digit number by a 1-digit number using partitioning Study Guide
- Multiply a 2-digit number by a 1-digit number using partitioning and representations (one regroup) Study Guide
- Multiply a 2-digit number by a 1-digit number using partitioning and representations (two regroups) Study Guide
- Multiply a 2-digit number by a 1-digit number using short multiplication (no regroups) Study Guide
- Multiply a 2-digit number by a 1-digit number using short multiplication (regrouping 10s to 100s) Study Guide
- Multiply a 2-digit number by a 1-digit number using short multiplication (regrouping 1s to 10s) Study Guide
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