Furthering understanding of subtraction as decreasing an amount
I can compare subtraction as decreasing an amount to other addition and subtraction structures.
Furthering understanding of subtraction as decreasing an amount
I can compare subtraction as decreasing an amount to other addition and subtraction structures.
Lesson details
Key learning points
- Subtraction can be seen as both partitioning and as decreasing an amount.
- Both types of subtraction stories are represented by the same equation.
- In an addition story, the amount at the start of the story is increased.
- In an subtraction story, the amount at the start of the story is decreased.
Common misconception
After exploring reduction, children may struggle to see partitioning as subtraction because a part is not taken away from the whole.
Make strong links between equations and different subtraction contexts by focusing on what the subtrahend represents in each case.
Keywords
Subtraction - To partition one part from another (the subtrahend from the difference), or to decrease an amount by taking an amount away.
Decrease - Make something smaller in size or quantity decrease.
Addition - To find the total, or sum, by combining two or more parts (addends), or to increase an amount by adding another.
Increase - To make something larger/greater in size or quantity.
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).
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