## Reflection: Subtracting with Decomposing - Section 3: Concept development

As seen in my reflection video, this was a smooth non-problematic lesson for my students.

My students are still getting used to the fact that they need to use numbers, words, and a model in their communication to me when solving problems.  I thought I might get some grumbles about now needing to check their subtraction work with addition, but, I didn't!  It is nice to see your students easily whip through an assignment, however, I can't honestly say that they whipped through it based on anything I did today.  The 9 subtraction problems they computed on the front side of the worksheet could have been done by most prior to my lesson. That being said, that side is still a great formative assessment for me to know if students need extra help or more support with subtraction.

I was really happy I got to use the word inverse when students noted the addition and subtraction relationship. I made a big dramatic scene about it and of course told them they wer using math practice 7!  The phrase that pays is also going well. I am finding my students trying to use it more and more.

Subtraction Success

# Subtracting with Decomposing

Unit 8: Place value
Lesson 13 of 14

## Big Idea: In this lesson, students use tape diagrams in order to subtract and make sense of subtraction as the inverse of addition.

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9 teachers like this lesson
Standards:
Subject(s):
Math, modeling, Place Value, Number Sense and Operations, subtraction, decompose numbers
60 minutes

### Melissa Romano

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