# Lesson 18

Una gráfica de barras pintada (optional)

### Lesson Purpose

The purpose of this lesson is for students to apply their understanding of bar graphs and addition and subtraction within 1,000 to write and solve questions that can be solved from information on a given bar graph.

### 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 analyze a bar graph that has some information obscured due to a paint splatter. Students determine if a question can be answered with the given bar graph. They use their understanding of addition and subtraction within 1,000 to answer the questions and generate their own mathematical question. They engage in a question exchange with their peers in the second activity to ask and answer the questions they write.

- Action and Expression

- MLR8

### Learning Goals

Teacher Facing

- Add or subtract 2 three-digit numbers using place value strategies that include composing or decomposing 2 units.
- Determine questions that can be answered by a given bar graph.
- Interpret data represented in a bar graph.

### Student Facing

- Resolvamos problemas en los que hay una gráfica de barras y que incluyen suma y resta.

### Required Preparation

### Lesson Timeline

Warm-up | 10 min |

Activity 1 | 15 min |

Activity 2 | 25 min |

Lesson Synthesis | 10 min |

### Teacher Reflection Questions

Reflect on times you observed students listening to one another’s ideas today in class. What norms would help each student better attend to their classmates' ideas in future lessons?

### Suggested Centers

- Target Numbers (1–5), Stage 6: Add Hundreds, Tens, or Ones (Addressing)
- Target Numbers (1–5), Stage 7: Subtract Hundreds, Tens, or Ones (Addressing)
- Five in a Row: Addition and Subtraction (1–2), Stage 8: Add within 1,000 with Composing (Addressing)
- How Close? (1–5), Stage 4: Add to 1,000 (Addressing)