The purpose of this activity is for students to learn Stage 1 of the Secret Fractions center. Students practice building non-unit fractions from unit fractions. Each partner starts with three “secret” non-unit fraction cards and five unit fraction cards. On their turn, students choose either to ask their partner for a unit fraction or to trade one of their secret fractions for a new secret fraction card. If the student has the requested secret fraction, they give it to their partner. If they do not have the requested unit fraction, they tell their partner to pick a unit-fraction card from the stack. After building each secret fraction, students reveal the secret fraction and explain how they made that fraction. For example, to complete a secret fraction card with , students need 3 cards with . A diagram is available in the blackline master that students can use to explain their thinking. The first student to build all three secret fractions wins. The Activity Synthesis highlights strategies students used to build their non-unit fractions.

Folders or other objects can be used to keep students’ work hidden.

• “¿Qué estrategias les ayudaron a construir sus fracciones secretas?” // “What strategies did you find helpful for building your secret fractions?” (When was my secret fraction, I was keeping track of how many cards I had to make . When I had as a secret fraction, I knew I needed cards, but I had a bunch of cards, so I traded for different secret fractions.)

The purpose of this activity is for students to use diagrams to represent situations that involve non-unit fractions. The Activity Synthesis focuses on how students partition and shade the diagrams and how the end of the shaded portion could represent the location of an object. When students interpret the different situations in terms of the diagrams, they reason abstractly and quantitatively (MP2).

• “¿Cómo partiste la tira en sextos?, ¿en octavos?” // “How did you partition the strip into sixths? Into eighths?”
• “¿Cómo podrías usar tercios para partir en sextos? ¿Cómo podrías usar cuartos para partir en octavos?” // “How could you use thirds to partition into sixths? Or use fourths to partition into eighths?”

• Display posters around the room.
• “Mientras observan cada póster, discutan cómo se muestra cada situación en el diagrama” // “As you look at each poster, discuss how each situation was shown on the diagram.” (The diagram was partitioned into 6 equal parts. 5 of the equal parts were shaded.)
• 2–3 minutes: partner discussion
• Share responses.
• “¿Qué parte de cada diagrama representa el lugar donde estaba escondido el objeto?” // “What part of each diagram would represent where the object was hidden?” (The end of the shaded part.)