The purpose of this activity is for students to create a connecting cube tower that is the same length as a given image. In the Activity Synthesis, students transition from describing the length of an object by comparing it to another object ("The earthworm is the same length as a tower of 8 cubes.") to describing the length of an object as a measurement ("The earthworm is 8 cubes long.").

• Invite previously identified students to share.
• Display the image of the dragonfly.
• “¿Cómo midieron la libélula?” // “How did you measure the dragonfly?” (I lined upthe first cube with one end of the dragonfly. Then I added cubes until I got all the way to the other end of the dragonfly.)
• “Como la torre de 4 cubos tiene la misma longitud que la libélula y cada cubo tiene la misma longitud, podemos decir que la libélula mide 4 cubos de largo” // “Since the tower of 4 cubes is the same length as the dragonfly and each cube has the same length, we can say the dragonfly is 4 cubes long.”
• For each animal, invite students to say, “ ____ mide ______ cubos de largo” // “The ______ is ___ cubes long.”

The purpose of this activity is for students to measure the lengths of images using connecting cubes. Although students have compared the lengths of objects in previous activities, length is defined in this activity since it is the first time students measure and describe the length of objects as a number of same-size length units.

Students determine how many connecting cubes long each image is. They make statements such as “The grasshopper is five cubes long.” Some students may disagree with their partner on how to measure based on where they start and end the measurement. This aspect of measuring length is the focus of the Activity Synthesis. When students disagree with each other and explain how they decided to measure each image, they critique the reasoning of others (MP3).

• Display answers.
• “Revisen sus medidas. ¿Encontraron las mismas medidas de longitud?” // “Check your measurements with these. Did you find the same measurements of length?”
• Consider asking:
  • “Si encontraron las mismas medidas, ¿qué hicieron ustedes y su pareja para asegurarse de haber encontrado la medida de longitud correcta?” // “If you found the same measurements, what did you and your partner do to make sure you found the right measurement of the length?”
  • “Si encontraron una medida diferente, ¿qué creen que pasó cuando midieron?” // “If you found a different measurement, what do you think happened when you measured?”

The purpose of this activity is for students to choose from activities that offer practice adding two-digit numbers within 100. Students choose any previously introduced stage from these centers:

• How Close?
• Target Numbers
• Five in a Row

• “Diego y Elena están jugando ‘Qué tan cerca’. Diego tiene una suma de 91. Elena tiene una suma de 89. ¿Quién recibe un punto por estar más cerca de 100? ¿Cómo lo saben?” // “Diego and Elena are playing How Close? Diego has a sum of 91. Elena has a sum of 89. Who gets a point for being closer to 100? How do you know?”