The purpose of this activity is for students to measure the length of their shoe using connecting cubes and solve a Put Together, Result Unknown problem and a Compare, Difference Unknown problem about their measurements. To solve the Put Together problem, students may put the connecting cube towers together and count all, count on, use known facts, or use methods such as making a ten. To solve the Compare problems, students may draw a diagram directly comparing the lengths then count up or count back or use known facts to determine the difference. When students find sums and differences using their measurements, they reason abstractly and quantitatively (MP2).

It is likely that students’ shoes will not be the length of an exact number of connecting cubes. Encourage students to write the closest number of whole units. There is no need to check students’ measuring techniques in this activity because the focus of the activity is solving story problems.

• Invite previously identified students to share.
• “¿En qué se parecen estas representaciones? ¿En qué son diferentes?” // “What is the same about these representations? What is different?” (The first two show the length of the shoes but the others just use numbers. They all find the difference between the lengths of the shoes.)

The purpose of this activity is for students to solve familiar story problem types in a measurement context. Students represent their thinking using drawings, numbers, words, or equations (MP2). Students may use the cubes or drawings to make sense of the problems if they choose. The Activity Synthesis focuses on a problem that can be represented as either addition or subtraction.

• Invite previously identified students to share.
• Consider asking:
  • “¿Cómo muestran ambos métodos la longitud del zapato de Diego, la longitud del zapato de su papá y la diferencia entre las dos longitudes?” // “How do both methods show the length of Diego's shoe, the length of his father’s shoe, and the difference between the two lengths?”
  • “¿En qué se parecen los métodos? ¿En qué son diferentes?” // “How are the methods the same? How are they different?”