To 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.

Find the missing part in addition and subtraction stories

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

First, I had 3 coins in my piggy bank.
Then, I saved another 6 coins. 
How many coins do I have in my piggy bank now?

First, I had 5 counters on my tens frame.
Then, 5 counters were added.
Now, there are ___ counters on my tens frame.

If the sum of my problem is 8, which of these equations could show the addends?

How many counters will be on the tens frame at the end of this subtraction story?

Which of these numbers, if subtracted from the amount at the start of this story, would leave the smallest amount at the end?

Write an equation for this 'First, then, now' story. 

Which equation correctly represents the story?
First, there were 6 stickers in my books. 
Then, I put some more in my book. 
Now, there are 9 stickers in my book.

Use the picture to help you complete the missing number equation.
___ + 2  = 6

Which tens frame shows the missing first part of this story?

At the start of the story, there was 1 egg in the egg box. 
At the end of the story, there were 6 eggs in the egg box.   
How many eggs were added?   

Which equation represents the story and shows the missing part?
We don't know how many pencils were in the pot at first.
Then, 3 pencils were added.
Now, there are 7 pencils in the pot.

Sam writes this equation to represent his story. 5 + ___ = 8
First, there were 5 cats on a wall. 
Then, ___ cats jumped onto the wall. 
Now, there are 8 cats on the wall.
What is the missing addend?

This lesson will soon be taken down.

Find the missing part in addition and subtraction stories

Lesson outcome