The purpose of this activity is for students to connect two-step word problems, diagrams, and equations with a symbol for the unknown quantity. Interpreting and relating given representations prepare students to use these as tools for reasoning when they solve two-step word problems. This sorting task gives students opportunities to analyze situations, diagrams, and equations closely and make connections (MP2).

• “Did you disagree on the placement of any cards? How did you come to an agreement?” (We went back and read the situation carefully together.)
• Choose a set of cards that belong together, such as G, C, and L, to discuss in detail. Ask, “How do the equation and the diagram represent the situation?”
• Attend to the language that students use to describe their matches and the situations, equations, and diagrams, and give students opportunities to describe them more precisely.

The purpose of this activity is for students to solve one of the problems from the card sort in the previous activity and examine their classmates' solutions to other problems. Students work in groups to create a poster of their solution. As students visit the posters, they leave comments about how they know the solution on the poster makes sense. As students make comments on the work of others, they critique the reasoning of others (MP3).

• “What are some ways that we could determine if the solution makes sense, without solving the problem?”
• “To determine if the solution makes sense, how could we use estimating? How could we use rounding?”

• Display posters around the room. If more than one group solved the same problem, consider displaying their posters together.
• Give each student a sticky note.
• “As you visit the posters, leave a comment on one poster that explains how you know the answer makes sense. Choose a poster that shows a problem different from the problem you solved."