Know that addition and subtraction are inverse operations
Lesson details
Learning outcome
I can recognise addition and subtraction as the inverse of each other.
Key learning points
- Addition is the inverse of subtraction. Addition can 'undo' subtraction.
- Subtraction is the inverse of addition. Subtraction can 'undo' addition.
- When a given amount is added to the start of a story, to 'undo' the change, we must subtract the same amount.
- When a given amount is subtracted from the start of a story, to 'undo' the change we must add the same amount.
Keywords
Add - o find the total, or sum, by combining two or more parts (addends), or to increase an amount by adding another.
Subtract - To partition one part from another (the subtrahend from the difference), or to decrease an amount by taking an amount away.
Inverse - Inverse means the opposite in effect; the reverse of.
Common misconception
Children may not understand the importance of the order of the numerals in equations, so may not understand that the amount added or subtracted is of key importance when undoing a change made.
Present errors to discuss and correct. Encourage children to use practical equipment to demonstrate how they know they are right or to show why an error made cannot be correct.
Teacher tip
To help connect the practical to pictorial representations and more abstract contexts, first ask children to act out scenarios, then represent pictorially alongside. Ensure that a range of practical and pictorial contexts are planned for and linked to the abstract.
Licence
Lesson video
Loading...
Prior knowledge starter quiz
6 Questions
Q1.Does this story show addition or subtraction?
Q2.What has been added in this story?
Q3.What has been subtracted in this story?
Q4.Which equation could represent this story?
Q5.Write an equation to represent this story.
First, 10 friends were playing a matching game together.
Then, 2 left to play another game.
Now, 8 friends are playing the matching game together.
Q6.What is missing from this story?
Assessment exit quiz
6 Questions
Q1.What amount would we subtract to undo the addition? Use the cubes to help you.
Q2.What amount would we add to undo the subtraction?
Q3.How would we undo the change in this story?
First, I had 9 pencils. Then, 2 pencils were taken. Now, I have 7 pencils.
9 − 2 = 7
Q4.Match each addition equation with the subtraction equation that can undo it.
7 − 3 = 4
6 − 1 = 5
3 − 3 = 0
Q5.Which of these pictures represent the inverse of 3 + 4 = 7
Q6.Which of these number pairs would complete this story?
To help you plan your 1 maths lesson on: Know that addition and subtraction are inverse operations, download all teaching resources for free and adapt to suit your pupils' needs...
To help you plan your 1 maths lesson on: Know that addition and subtraction are inverse operations, 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 1 maths lessons from the Additive structures: addition and subtraction unit, dive into the full primary maths curriculum, or learn more about lesson planning.