New
New
Multiply a 2-digit number by a 1-digit number using expanded multiplication (regrouping 1s to 10s)
I can use expanded multiplication to record regrouping from the 1s to the 10s
Lesson 6 of 10
New
New
- Year 5
Multiply a 2-digit number by a 1-digit number using expanded multiplication (regrouping 1s to 10s)
I can use expanded multiplication to record regrouping from the 1s to the 10s
Lesson details
Key learning points
- If the product of the ones digits is greater than 10, you regroup ten ones into one ten.
- If the product of the ones digits is greater than ten, the partial product will be a 2-digit number.
- There are similarities between the representations of multiplication.
Keywords
Regrouping - The process of unitising and exchanging between place values is known as regrouping.
Expanded multiplication - Expanded multiplication is a way of recording a calculation focusing on partitioning one or more factors and showing partial products.
Common misconception
Pupils may not align or regroup correctly leading to an inaccurate calculation.
Continue to ask what each digit that has been recorded represents. Demonstrate the regrouping using base ten blocks to help.
Ensure children are able to generalise that if the ones digits is greater than ten, the partial product will be a 2-digit number.
Teacher tip
Licence
This content is © Oak National Academy Limited (2025), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).
Lesson video
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Prior knowledge starter quiz
6 Questions
Q1.21 ones are equivalent to __________.
21 ones are equivalent to __________.
2 tens and 1 ten
1 ten and 2 ones
2 ten and 2 ones
Q2.Look at this equation. The numbers highlighted in purple are known as .
Look at this equation. The numbers highlighted in purple are known as .
products
partial products
addends
Q3.Select the correct representation for this multiplication.
Select the correct representation for this multiplication.
Picture 2
Picture 3
Q4.The multiplication is: 73 × 2 Which short multiplication shows this correctly?
The multiplication is: 73 × 2 Which short multiplication shows this correctly?
Picture 2
Q5.Which representation will require regrouping?
Which representation will require regrouping?
A
C
Q6.Match the representations A, B and C to the correct multiplication equation.
Match the representations A, B and C to the correct multiplication equation.
Assessment exit quiz
6 Questions
Q1.Look at the image. The arrows are pointing to __________.
Look at the image. The arrows are pointing to __________.
factors
products
addends
Q2.Select the correct expanded method shown by this representation.
Select the correct expanded method shown by this representation.
picture 1
Q3.Sofia believes that you always have a 1-digit partial product when multiplying a 2-digit by a 1-digit number. What do you think?
Sofia believes that you always have a 1-digit partial product when multiplying a 2-digit by a 1-digit number. What do you think?
This is always true.
This is never true.
Q4.Which multiplication will need regrouping in the ones column only?
Which multiplication will need regrouping in the ones column only?
71 × 3
10 × 3
77 × 3
Q5.Using Lucas’s grid model, fill in the gap for the expanded multiplication.
Using Lucas’s grid model, fill in the gap for the expanded multiplication.
Q6.Use expanded multiplication to calculate: 3 × 19
Use expanded multiplication to calculate: 3 × 19
