• “¿Qué patrón observaron en estas expresiones?” // “What pattern did you notice with these expressions?”
• “¿Cómo les ayudó pensar en componer una decena a encontrar los valores mentalmente?” // “How did thinking about composing a ten help you solve mentally?” (Each time, the first number was only 2 away from a ten, which was a more friendly number.)

The purpose of this activity is for students to match story problems, in the context of money, to tape diagrams. Students make sense of stories and determine which diagram represents each situation. One pair of problems are one-step stories while the other pair are two-step stories. The numbers in the stories are the same, so students will have to focus on the relationships between the quantities in the stories to match them to tapes (MP2).

Students may choose and justify matches different from those given in the student responses (MP3). For example, diagram B could match Jada’s story. But this story is a comparison and naturally matches diagram C, whereas both parts of diagram B make up Diego’s money. Both two-step problems as well, could be represented by either diagram A or diagram D. For the basketball story, we know that the basketball costs $ less than the football and the soccer ball combined. For the clothes, we know that the pants cost $ and want to know how much more the shirt and the shoes cost. Diagram A matches the clothes story because the price of the pants, 39, is known but the difference is not known. Diagram D matches the basketball story because the difference, 39, is known.

The purpose of this activity is for students to solve two-step problems, without the scaffold of having the first step explicitly stated. Students solve in a way that makes sense to them and may use diagrams to help them make sense of the story. In the Activity Synthesis, the tape diagram is highlighted.