# Lesson 14

Cientos de objetos (optional)

### Lesson Purpose

### Lesson Narrative

This lesson is optional because it does not address any new mathematical content standards. This lesson does provide students with an opportunity to apply precursor skills of mathematical modeling.

In this lesson, students build on their previous understandings and experiences with representations of numbers between 100 and 999. Students use their understanding of the base-ten structure of numbers to count and represent quantities of real-world objects (MP7). When students investigate the advantages and disadvantages of different methods of counting a large number of objects and then choose a method to use they critique the reasoning of others and model with mathematics (MP3, MP4).

- Representation

- MLR7

### Learning Goals

Teacher Facing

- Count and represent three-digit numbers using place value understanding.

### Student Facing

- Usemos el valor posicional para contar objetos del mundo real.

### Required Materials

Materials to Gather

### Required Preparation

Activity 2:

- Each group of 2 to 4 students will need between one-half cup to one cup of beans or other small objects to count. If real-world objects are unavailable, centimeter cubes could be used instead.

### Lesson Timeline

Warm-up | 10 min |

Activity 1 | 10 min |

Activity 2 | 25 min |

Lesson Synthesis | 10 min |

### Teacher Reflection Questions

### Suggested Centers

- Mystery Number (1–4), Stage 2: Three-digit Numbers (Addressing)
- Greatest of Them All (1–5), Stage 2: Three-digit Numbers (Addressing)
- Get Your Numbers in Order (1–5), Stage 2: Three-digit Numbers (Addressing)