# Lesson 7

### Lesson Purpose

The purpose of this lesson is to activate the strategies students have for subtracting numbers within 1,000.

### Lesson Narrative

In grade 2, students subtracted numbers within 1,000 using various strategies based on place value and the associative and commutative properties of addition. They used base-ten blocks, base-ten diagrams, equations, and number lines to represent their reasoning.

In this lesson, they review a variety of strategies with an emphasis on subtracting hundreds and hundreds, tens and tens, and ones and ones. Students should have access to base-ten blocks.

• Representation
• MLR8

### Learning Goals

Teacher Facing

• Subtract within 1,000 in a way that makes sense to them.

### Student Facing

• Let’s subtract numbers within 1,000.

### Required Materials

Materials to Gather

### Lesson Timeline

 Warm-up 10 min Activity 1 25 min Activity 2 10 min Lesson Synthesis 10 min Cool-down 5 min

### Teacher Reflection Questions

What strategies are students most comfortable using to subtract within 1,000? How will you leverage that student understanding in upcoming lessons on subtraction algorithms?