The purpose of this activity is for students to determine what information is necessary to solve a story problem. This will be useful in the next activity when students create their own story problem to match an expression, because they will need to decide what information to include. When students identify information they need to know and don’t need to know to answer a question, they model with mathematics (MP4).

• “¿Qué expresión podemos usar para mostrar lo que ocurrió en el problema-historia? ¿Cómo lo saben?” // “What expression can we use to show what happened in the story problem? How do you know?” (  or . Mai collected 3 rocks and Diego collected 6 rocks.)
• “Podemos usar la expresión   para mostrar lo que ocurrió en el problema-historia. Mai recogió 3 piedras y Diego recogió 6 piedras. Recogieron juntos 9 piedras” // “We can use the expressions  to show what happened in the story problem. Mai collected 3 rocks and Diego collected 6 rocks. They collected 9 rocks together.”
• “  es 9. Podemos escribirlo como   es 9” // “  is 9. We can write that as  is 9.”
• Write “  is 9.”

The purpose of this activity is for students to tell a story problem that matches a given expression. Students make decisions about the real-world situations they describe to represent the expression. Also, they figure out which information to include so that the story problem matches the expression and can be solved. When students consider assumptions about information not given in a situation and identify information they need to know and don’t need to know to answer a question, they model with mathematics (MP4).

• “¿La expresión de su compañero le corresponde a su problema-historia? ¿Qué información de la historia les ayuda a averiguarlo?” // “Does your partner’s expression match their story problem? What information in the story helps you figure that out?” (Yes, in the story there were 5 red apples and 2 green apples. That matches the expression 5 + 2. I needed to know how many apples of each color there were.)
• “Cuando estaban creando su problema-historia, ¿hubo alguna información que decidieron no incluir? ¿Por qué sí o por qué no?” // “When you were creating your story problem, was there any information that you decided not to include? Why or why not?” (I didn't include the color of the jump rope because you didn't need that to find how many times Lin jumped.)
• As time allows, invite students to share the story problems they created with the class.
• As each student shares, consider asking:
  • “¿Qué relación hay entre el problema-historia y la expresión?” // “How does the story match the expression?”
  • “¿Qué información necesitamos para responder la pregunta?” // “What information do we need to answer the question?”