# Lesson 16

Día 3 de centros

### Lesson Purpose

The purpose of this lesson is to practice working with numbers to 120 and measuring lengths.

### Lesson Narrative

In the first activity, students learn stage 3 of the Counting Collections center. In this new stage, students count and represent collections of up to 120 objects. In the second activity, students choose between two previously introduced centers focused on measuring and writing numbers.
• Representation
• MLR8

### Learning Goals

Teacher Facing

• Count groups of up to 120 objects and write a number to represent them.
• Measure length by iterating same-size length units without gaps or overlaps.
• Read and write numbers to 120.

### Student Facing

• Practiquemos cómo contar, medir longitudes y escribir números.

### Required Materials

Materials to Gather

Materials to Copy

• Counting Collections Stage 3 Recording Sheet, Spanish

### Required Preparation

Activity 1:

• Create a collection of up to 120 objects per group of 2 students (buttons, two-color counters, linking cubes, paper clips, pattern blocks, square tiles).

Activity 2:

• Gather materials from:
• Write Numbers, Stages 1–3
• Estimate and Measure, Stage 1

### Lesson Timeline

 Warm-up 10 min Activity 1 20 min Activity 2 20 min Lesson Synthesis 10 min

### Teacher Reflection Questions

Think about a time you recently made a mistake during math class. How did you leverage your mistake to show students that mistakes are just learning in process?