# Lesson 4

Rompecabezas de fichas geométricas y ecuaciones

### Lesson Purpose

The purpose of this lesson is for students to relate addition equations to shapes made with 2 kinds of pattern blocks.

### Lesson Narrative

In previous units, students have related expressions and equations to story problems, objects, and drawings. Students have separately made sense of equations with the total first (\(3 = 2 + 1\)) and with the addends first (\(2 + 1 = 3\)). In this lesson, students work with both forms of equations in the same activity, which requires them to attend to the placement and meaning of the plus sign. In this lesson, students hear equations read with the term “equals” rather than “is” for the first time. In future lessons, students will use equations to represent story problems about pattern blocks.

- Engagement

- MLR8

### Learning Goals

Teacher Facing

- Match addition equations to shapes with two kinds of pattern blocks.

### Student Facing

- Usemos ecuaciones para mostrar cuántas hay de cada figura.

### Required Materials

Materials to Gather

### Required Preparation

Activity 1:

- Create a shape with 1 red trapezoid pattern block and 4 green triangle pattern blocks to display in the activity synthesis.

Activity 3:

- Gather materials from:
- Pattern Blocks, Stages 1-7
- Geoblocks, Stages 1 and 2
- Grab and Count, Stage 1
- Find the Pair, Stages 1 and 2

### Lesson Timeline

Warm-up | 10 min |

Activity 1 | 10 min |

Activity 2 | 10 min |

Activity 3 | 25 min |

Lesson Synthesis | 5 min |

Cool-down | 0 min |

### Teacher Reflection Questions

In grade 1, students make sense of the meaning of the equal sign and determine if equations involving addition and subtraction are true or false. How does the work in this lesson prepare students for this work in grade 1?