Reflection: Intervention and Extension Counting Backwards Works Too - Section 2: Teaching The Lesson


When we started talking about subtraction, one of my students was not trying to solve the problem. When I asked her why she said, "I don't do subtraction." When I questioned her more about this she said that she only does addition. Her teacher told her that was ok in first grade.

While I doubt that is what the teacher meant, it is possible that the child was encouraged to make an addition sentence out of a subtraction sentence, but developmentally she wasn't ready for this reversal. She was unable to tell me that the answer to a subtraction problem would be smaller than the number you start with. Her concept of number was very weak as shown by this problem seeing that subtraction makes a number smaller.

As teachers we need to start where are children are in their understanding, regardless of the standards children need to meet in a given year. If they do not have the foundation necessary, we must go back and reteach those concepts before expecting them to go forward. The foundation is critical to the building of later understandings.

I will start with the basics of subtraction with this child. I hand her blocks and ask her to show me 12 blocks. Now I ask her to take away 4 of them. How many are left? She counts and says 8. I tell her she just did subtraction. We do several other problems to show her that she really can do subtraction. 

  Intervention and Extension: I Don't Do Subtraction
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Counting Backwards Works Too

Unit 2: Adding and Subtracting the Basics
Lesson 4 of 18

Objective: SWBAT count back on a number line or number grid to complete subtraction problems and subtraction number stories.

Big Idea: Students are more confident counting up, however, counting back is crucial to understanding subtraction. It needs to be taught and practiced more frequently.

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