New
New
Year 1
Understand subtraction as decreasing an amount
I can describe and interpret subtraction stories which involve decreasing an amount and write equations to represent this.
New
New
Year 1
Understand subtraction as decreasing an amount
I can describe and interpret subtraction stories which involve decreasing an amount and write equations to represent this.
Lesson details
Key learning points
- Decreasing the first amount in a story is a type of subtraction.
- It can be represented as a ‘First, then, now’ story.
- It can also be represented as an equation.
- The first amount in a ‘First, then, now’ story must be written first in an equation.
Common misconception
Children may find the ‘then’ part of the story, where the amount changes, difficult to identify.
Draw attention to the change, talking about it as a decrease.
Keywords
First - Before anything else.
Then - After something in time.
Now - At the present time.
Decrease - Make something smaller in size or quantity.
Draw attention to how the reduction structure of subtraction is different to partitioning. Use 'take away' interchangeably with 'subtract' here to help highlight that the subtrahend is physically taken away rather than just 'partitioned' from the difference.
Teacher tip
Licence
This content is © Oak National Academy Limited (2024), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).
Video
Loading...
Starter quiz
Download starter quiz
6 Questions
Q1.
Write a subtraction equation that could represent the counters.
Q2.
What subtraction equation could represent this story?
There were 5 children altogether in the whole group.
1 had brown hair.
How many did not have brown hair?
Q3.
Alex writes this addition equation to represent the bar model.
2 + 7 = 9
Which subtraction equation could also be represented by the bar model?
Q4.
Which set of counters could represent this story?
There were 6 teddies altogether in the whole group.
4 were small teddies.
How many were not small teddies?
Q5.
Tick the subtraction equations which could be represented by this bar model.
3 + 6 = 9
Q6.
Which of these is a subtraction story?
There are 3 birds in the tree and 2 on the fence. How many birds are there?
Exit quiz
Download exit quiz
6 Questions
Q1.
Alex writes an equation to match his story.
7 - 2 = 5
What does the 5 represent?
The amount at the start of the story.
The amount subtracted.
Q2.
Which story could match this picture?
First, there were 3 pencils. Then, 2 were put in. Now, there are 5 pencils.
First, there were 5 pencils. Then, 3 were taken. Now, there are 2 pencils.
Q3.
Which set of counters would represent this story?
First, there were 10 pounds in my pocket.
Then, I spent 4 pounds.
Now, there are 6 pounds in my pocket.
Q4.
Which equation matches the picture?
5 + 2 = 7
7 - 5 = 2
Q5.
Which equation matches the story?
5 - 3 = 8
8 - 5 = 3
Q6.
Write an equation to match the picture.
