The purpose of this activity is for students to create equations that represent familiar story problems. Students also compare the story problems to describe how they are the same and different. This activity focuses on problem types that students are most familiar with:

• Add To, Result Unknown
• Put Together/Take Apart, Total Unknown
• Take From, Result Unknown
• Put Together/Take Apart, Addend Unknown

As students compare the story problems, they may notice differences in the structure of the problems and continue to describe stories that include actions and those that are about part-part-whole relationships. The equations also provide another way to compare story problems as students may notice how the same operations may be used to solve different kinds of problems or as they compare story problems that include an unknown addend and those that do not.

During the Synthesis, students discuss a Put Together, Both Addends Unknown problem and consider how the structure of the problem is different from the others.

• Invite 1–2 students to share the equations they wrote for each story problem.
• Consider asking:
  • “¿Qué relación hay entre tu ecuación y la historia?” // “How does your equation match the story?”
• As needed ask, “¿En alguna historia podías usar una ecuación de suma o de resta? ¿En cuál? ¿Cómo sabes que podías usar ambas ecuaciones?” // “Were there any stories that you could use an addition or subtraction equation? Which one? How do both equations match?”

The purpose of this activity is for students to represent and solve story problems, including representing them with equations. Students are divided into 8 groups and each group gets one of the story problem cards used in previous lessons. Students individually solve the story problem and write an equation to match it before creating a poster with their group. During the Synthesis, students explain how the equations match the story problem. When students recognize that the numbers in the equations represent specific quantities in the story problems, they reason abstractly and quantitatively (MP2).

Students may create equations before they solve or after they solve. They may also use equations with an unknown or with the known quantities after they’ve solved the problem. The focus should remain on students explaining the connections between their equations and the problems and discussing how equations can be a useful tool for representing a problem or communicating how they solved a problem.

The story problems used in this activity are the same as those used in the previous “Card Sort: Match Stories and Equations” activities so that reading the problems is more accessible. Depending on the reading ability of your class, consider adapting the lesson to involve partner or group reading before students solve independently. As students begin the activity, consider which groups may be most important to listen to first to ensure reading is not a barrier to accessing the mathematics.

• Display previously identified posters.
• Reread the related story problems as needed.
• “¿Qué relación hay entre la ecuación que escribió cada grupo y el problema-historia?” // “How does the equation each group wrote match the story problem?”