The purpose of this activity is for students to represent and solve Compare story problems. Students label a tape diagram based on the given information and represent the unknown with a question mark. When students connect the story problem and the diagram, they look for and make sense of the structure of the problem (MP2).

In the Launch of the activity, it may be helpful to ask students to share what they know or have questions about in regards to a library to ensure each student has access into the context and understands books are checked out and returned.

• Display student work for the first problem.
• Students explain their work, describing how they used the tape diagram.
• “Does anyone have a question for _____ about their thinking or work?”
• “How did you know where to put the numbers and the question mark in this problem?”
• Repeat for the second problem.

This activity begins with the use of the Three Reads Math Language Routine. This routine helps students practice a way to make sense of a problem and persevere in solving it (MP1). The purpose of this activity is for students to analyze and solve a variety of Compare problems. Students may use tape diagrams or any other method that makes sense to them to solve each story problem. Monitor for the different methods students use, including drawings other than tape diagrams and the use of equations. Also, monitor how students compute and describe their computations when finding the unknown values. Listen for methods based on place value and making a ten.

Students begin the activity by looking at the first story problem displayed, rather than in their books.  At the end of the Launch, students open their books and work on the story problems. If students do not show their reasoning using a tape diagram and their equation does not match the story problem, ask them to describe the mathematics of the story problem by explaining what each quantity represents in the context of the story. As needed, draw an unlabeled tape diagram to support student thinking.

This activity uses MLR6 Three Reads. Advances: reading, listening, representing.

• Display student work that shows different ways to represent how many more minutes Jada spent reading. 
• “What’s the same about their representations? What’s different?”
• 1 minute: quiet think time
• 1 minute: partner discussion
• “How did your representation help you decide whether to add or subtract?”
• If time, discuss computation strategies:
  • Add and subtract tens with tens (problems 2 and 3).
  • Decompose to make a ten (problem 4).