o find the total, or sum, by combining two or more parts (addends), or to increase an amount by adding another. 

To partition one part from another (the subtrahend from the difference), or to decrease an amount by taking an amount away. 

Inverse means the opposite in effect; the reverse of.

Know that addition and subtraction are inverse operations

Maths

In this unit pupils will find missing addends in equations. They will partition a whole into 2 parts representing first, then, now stories with subtraction equations. They will learn + and - are inverse operations. In the future unit pupils will explain that addition is commutative. They will find pairs of numbers to 10 and add or subtract 1 from any number.

In prior learning, pupils will have learnt to count confidently and have developed a deep understanding of the numbers to 10, the relationships between them and the patterns within those numbers. In this unit pupils will find missing addends. They will partition a whole into two parts and represent it with subtraction equations learning that addition and subtraction are inverse operations.

Additive structures: addition and subtraction

What amount would we subtract to undo the addition? Use the cubes to help you.

What amount would we add to undo the subtraction?

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

Match each addition equation with the subtraction equation that can undo it.

Which of these pictures represent the inverse of 3 + 4 = 7

Which of these number pairs would complete this story?

Does this story show addition or subtraction?

Which equation could represent this story?

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.

This lesson will soon be taken down.

Know that addition and subtraction are inverse operations

Lesson outcome