1. Problem Structures: Comparing
Unit of Study: Addition and Subtractions Concepts within 10
Global Concept Guide: 3 of 5

2. Content Development
Students will work through the three day GCG on the problem structure comparing.

3. Content Development 6-4= 4+ =6
“Comparison situations differ from taking from and taking apart situations in that they involve only two discrete quantities that are not parts of a whole or related in that way..” GO Math Chapter 2 TE, pg. 73A
The terms “more” , “less” and “fewer” when used to compare can create confusion. Students generally can identify who has more, but do not recognize how many more. Students need experience with both terms.
Take the opportunity to expose students to addition sentences with missing addends as related to the problems.
6-4= =6

4. Day 1
Day 1 focuses on having students use snap cubes to build number trains and compare quantities.
It is necessary for students to physically place number trains side by side and count the difference.
The Voyages lesson Compare makes a natural connection between number trains and number lines.

5. Day 2
After working with manipulatives on day 1, students will work with picture representations of the problem on the second day.
Allow students to continue the use of manipulatives to model if needed, but encourage them to draw quick models (i.e. circles, tallies, etc.) to assist.
It is essential for students to see that the numerical answer can be the same for a problem whether being asked how many more or how many less, but the answer represents a different part of the problem.
Snap Cubes
Quick Picture

6. Day 3
Probe students and facilitate the discussion that the models created with manipulatives are directly related to the bar model. Number lines and snap cubes can help clarify this.
Differentiate the problems given to students based on needs. For example, #4 on page 75 might be more appropriate for a below level student, where as #5 could challenge your on level and above level students.
Great discussion starter:
How does the snap cube model compare to the bar model?

7. Enrich/Reteach/Intervention
Create compare story problems
Create index cards for matching scenarios with equations and representations (including missing addends)
Reteach
Grab and Go Center Big Idea 1: Activities 16/17
Intervention/Small Group
GO Math Grade 1 Chapter 2 TE - Rti Tier 2 Activities pages 69B and 73B
GO Math Grade 1Rti Strategic Intervention Guide – Skill 12