Lesson 15

The purpose of this warm-up is to draw students’ attention to story contexts, which will be useful when students make story problems about fruit in a later activity.

• Groups of 2
• Display the image.
• “¿Qué observan? ¿Qué se preguntan?” // “What do you notice? What do you wonder?”
• 1 minute: quiet think time

• “Discutan con su compañero lo que pensaron” // “Discuss your thinking with your partner.”
• 1 minute: partner discussion
• Share and record responses.

• “¿En qué otras situaciones aparecen frutas?” // “What are some other situations that involve fruit?” (shopping for fruit, paleta flavors, fruit in baskets and on shelves, people and animals picking and eating fruit, fruit that comes in more than one color, making juice, growing fruit)

The purpose of this activity is for students to generate Put Together/Take Apart, Both Addends Unknown story problems involving fruit.

In the activity synthesis, students select at least one problem to share with a different group in preparation for the next activity.

• Each group of 2 needs 1 connecting cube.

• Groups of 2
• Give each group of students a number mat, a connecting cube, and access to two-color counters.
• Display the student page and number mat.
• “Vamos a contar historias matemáticas usando dos tipos diferentes de tableros. ¿Qué observan?” // “We’re going to tell math stories using two different kinds of mats. What do you notice?” (One mat has pictures of fruit and the other has numbers.)
• 30 seconds: quiet think time
• Share responses.
• “Voy a lanzar el cubo en el tablero de frutas. Así sabré sobre cuáles frutas debo contar una historia” // “I will roll the cube onto the fruit mat. This tells me which fruit to tell a story about.”
• “Voy a lanzar el cubo en el tablero de números. Así sabré cuántas frutas tengo en total” // “I will roll the cube onto the number mat. This tells me how many pieces of fruit I have altogether.”
• Demonstrate telling a Put Together/Take Apart, Both Addends Unknown story problem with the class. Keep the example displayed as students work.
• “Ustedes van a narrar problemas-historia sobre frutas. Primero, lancen el cubo para saber cuál es su fruta y su número. Después, narren una historia sobre esa cantidad de frutas sin decir cuántas hay de cada tipo de fruta. Las preguntas de su historia deben ser sobre cuántas puede haber de cada tipo. Pueden escribir palabras o hacer dibujos para recordar el problema-historia que inventen” // “You will tell story problems about fruit. First, roll the cube to find out your fruit and your number. Then tell a story about that many pieces of fruit without telling how many of each kind of fruit there are. The questions in your story should ask about how many of each type there could be. You can write words or draw pictures to help you remember the story problem that you create.”

• 5 minutes: independent work time

• “Cuéntenle su problema-historia a su compañero” // “Tell your partner your story problem.”
• 1 minute: partner discussion
• “Resuelvan el problema-historia que les contó su compañero. Muestren cómo pensaron. Usen objetos, dibujos, números o palabras” // “Solve the story problem your partner told you. Show your thinking using objects, drawings, numbers, or words.”
• 5 minutes: partner work time

The purpose of this activity is for students to find all possible solutions to a Put Together/Take Apart, Both Addends Unknown story problem using patterns that were investigated in previous lessons. In previous lessons students have found more than 1 solution to a Put Together/Take Apart, Both Addends Unknown story problem. Students are encouraged to find all possible solutions in this optional activity, which is not required by the standards. As students share their solutions, encourage them to record their drawings and solutions systematically. Pair students with a different partner than in the previous activity.

• Each group of 2 needs at least 10 two-color counters.

• Groups of 2.
• Give students access to two-color counters.
• “Cuéntenle su problema-historia a su nuevo compañero” // “Tell your new partner your story problem.”
• 30 seconds: quiet think time
• 1 minute: partner discussion
• “¿Qué están tratando de averiguar?” // “What are you trying to figure out?”
• 30 seconds: quiet think time
• 1 minute: partner discussion

• “Con su compañero, muestren tantas soluciones posibles del problema-historia como puedan” // “Work with your partner to show as many possible solutions for the story problem as you can.”
• “Muestren cómo pensaron. Usen dibujos, números, palabras u objetos” // “Show your thinking using drawings, numbers, words, or objects.”
• 5 minutes: partner work time
• As students work consider asking:
  • “¿Creen que encontraron todas las soluciones de su problema?” // “Do you think you found all the solutions for your problem?”
  • “¿Cómo pueden organizar su trabajo para mostrar que tienen todas las soluciones?” // “How can you organize your work to show that you have all the solutions?”

• Invite students to share their stories and solutions.
• Record each student solution with an equation.