SWBAT define and explain what it means to subtract.

When we teach others, we build our own understanding.

5 minutes

*We have done a lot of work on understanding subtraction and what it means to subtract. Today we are going to create presentations* (MP3 - Construct viable arguments and critique the reasoning of others)* and posters explaining what we know about subtraction and showing examples *(MP4 - Model with mathematics).

*I always understand things much better when I explain them or teach them to you, so today you will get a turn to teach all of us what you know!*

My goal for this lesson is to have students use pictures, numbers and their own words to explain the concept of subtraction. They are defining what subtraction means to them, showing examples of subtraction problems and showing various ways that the problems can be solved. This reinforces our classroom commitment to finding multiple ways to problem solve. Instead of me always defining what the 'correct' way looks like, I allow students to show it in the way that makes the most sense to them.

30 minutes

*As a group you will need to design a rough draft for your poster. The only things I will require is that you have a definition and an example* (MP4 - Model with mathematics).

*Other than that, it is up to your group how you want to present the information and teach the rest of us about what it means to add* (MP3 - Construct viable arguments and critique the reasoning of others). *We will present at the end of our time today, so make sure you stay focused and on task.*

15 minutes

*I can’t wait to learn from all of you today! Remember to project your voice, and when you finish your presentation we will ask questions about your poster, so be prepared to defend your choices!*