Subtract 3-digit multiples of 10 by finding the difference between them
Lesson details
Learning outcome
I can subtract 3-digit multiples of 10 by finding the difference between them.
Key learning points
- When numbers are close together, the difference between them is small.
- Finding the difference means we count on from the subtrahend to the minuend.
- A number line or a bar model can represent finding the difference.
Keywords
Minuend - The minuend is the number being subtracted from.
Subtrahend - A subtrahend is a number subtracted from another.
Difference - The difference is the result after subtracting one number from another.
Common misconception
Children will often reverse the minuend and subtrahend because they don't always appear in the order that they would in an expression.
Give time to ensure that the children understand the bar model representation and encourage them to discuss which number is the minuend and which is the subtrahend before engaging in a strategy for mental subtraction.
Teacher tip
This strategy is shown with number lines and jottings but the end goal is for the children be able to do it mentally so try to reduce such supports as quickly as possible. The spinners can be replaced with digit dice, digit cards or any random digit generator.
Licence
Lesson video
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Prior knowledge starter quiz
6 Questions
Q1.Which of these subtraction expressions can be more efficiently solved by finding the difference?
Q2.What is the missing part in this bar model?
Q3.Match the numbers so that they make a pair with a sum of 100.
80
60
25
5
Q4.Use a find the difference strategy to calculate: 54 − 47 =
Q5.Use a partitioning strategy to find the sum of 135 and 270
Q6.Select all the multiples of 10
Assessment exit quiz
6 Questions
Q1.Which of these is the correct equation represented by this bar model?
Q2.Which of these is the correct equation represented by this number line?
Q3.What is the difference between the two values shown in the bar model?
Q4.What is the difference between the two values shown?
Q5.What is the difference between the two values shown?
Q6.Which of the pairs of numbers have the greatest difference?
To help you plan your 3 maths lesson on: Subtract 3-digit multiples of 10 by finding the difference between them, download all teaching resources for free and adapt to suit your pupils' needs...
To help you plan your 3 maths lesson on: Subtract 3-digit multiples of 10 by finding the difference between them, 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 Informal and mental strategies for adding and subtracting two 3-digit numbers unit, dive into the full primary maths curriculum, or learn more about lesson planning.