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

Make something smaller in size or quantity decrease.

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

To make something larger/greater in size or quantity.

Furthering understanding of subtraction as decreasing an amount

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

A monkey has 7 bananas. She eats 5 of them. How many bananas does she have left?

Which equation matches this 'First, then, now' story?

Write an equation to represent this story.

Is this number line showing an increase or a decrease from the amount at the start of the story?

Is this story showing an increase or a decrease from the first amount?

6 - 2 = 4
First, there were 6 apples on the plate. 
Then, 2 apples were taken off the plate. 
Now, there are 4 apples on the plate. 
What does the 2 represent in this story?

First, there were 5 birds. Then, 1 flew off. Now, there are 4 birds.

First, there were 5 birds. Then, 4 flew off. Now, there are 4 birds.

First, there were 4 birds. Then, one flew in. Now, there are 5 birds.

First, there were 8 cars. Then, 4 drove away. Now, there are 4 cars.

First, there were 5 dogs. Then, 5 ran away. Now, there are 0 dogs.

First, there were 10 birds. Then, 6 flew away. Now, there are 4 birds.

Match the story to the equation it represents.

This lesson will soon be taken down.

Furthering understanding of subtraction as decreasing an amount

Lesson outcome