Multiply a 3-digit by a 1-digit number with one or two regroups
Lesson details
Learning outcome
I can multiply a 3-digit by a 1-digit number using expanded and short multiplication (one or two regroups).
Key learning points
- If the product of the ones digits is greater than 10 then you regroup ten ones into one ten.
- If the product of the 1-digit number and the tens digit is greater than 100 then you regroup ten 10s into one 100
- If the product of the 1-digit number and the 100s digit is greater than 1,000 then you regroup ten 100s into one 1,000
Keywords
Regroup - The process of unitising and exchanging between place values is known as regrouping.
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.
Common misconception
Children may misalign digits when arranging into the short multiplication layout.
Children should use unitising language to help them understand and apply this to formal written methods.
Teacher tip
Draw attention to regrouping. ‘If there are ten or more tens, we must regroup the tens into hundreds and tens.’
Licence
Lesson video
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Prior knowledge starter quiz
6 Questions
Q1.What’s the next number in the sequence: 11, 22, 33, ___
Q2.Look at the short multiplication. ___ tens have been regrouped.
Q3.Look at the expanded multiplication. tens have been regrouped.
Q4.Select the representation which shows: 42 × 3
Q5.Use a formal or informal method to solve this word problem: If all these boxes are the same height, how tall is the stack of boxes?
Q6.Find the missing number.
Assessment exit quiz
6 Questions
Q1.Which multiple is the odd one out?
Q2.Select the correct expanded arrangement for:
Q3.Which multiplication will need regrouping in the ones column only?
Q4.Use expanded multiplication to solve: 422 × 4. Write the product in numeral form.
Q5.Use short multiplication to solve: 406 × 6. Write the product in numeral form.
Q6.What could the missing number be?
To help you plan your 5 maths lesson on: Multiply a 3-digit by a 1-digit number with one or two regroups, download all teaching resources for free and adapt to suit your pupils' needs...
To help you plan your 5 maths lesson on: Multiply a 3-digit by a 1-digit number with one or two regroups, download all teaching resources for free and adapt to suit your pupils' needs.
The starter quiz will activate and check your pupils' prior knowledge, with versions available both with and without answers in PDF format.
We use learning cycles to break down learning into key concepts or ideas linked to the learning outcome. Each learning cycle features explanations with checks for understanding and practice tasks with feedback. All of this is found in our slide decks, ready for you to download and edit. The practice tasks are also available as printable worksheets and some lessons have additional materials with extra material you might need for teaching the lesson.
The assessment exit quiz will test your pupils' understanding of the key learning points.
Our video is a tool for planning, showing how other teachers might teach the lesson, offering helpful tips, modelled explanations and inspiration for your own delivery in the classroom. Plus, you can set it as homework or revision for pupils and keep their learning on track by sharing an online pupil version of this lesson.
Explore more key stage 2 maths lessons from the Multiplication by partitioning leading to short multiplication (3 by 1-digit) unit, dive into the full primary maths curriculum, or learn more about lesson planning.