# Lesson 10

Using Algorithms with Partial Products: 2 Two-digit Numbers

### Lesson Purpose

The purpose of this lesson is for students to use partial products in an algorithm to multiply 2 two-digit numbers.

### Lesson Narrative

In the previous lesson, students learned to record the partial products from multiplying vertically, using an algorithm. They made connections between the new notation to the structure of the rectangular diagram on which they used earlier. In this lesson, students apply that work to 2 two-digit factors.

• Representation
• MLR8

### Learning Goals

Teacher Facing

• Multiply 2 two-digit numbers using an algorithm that uses partial products.

### Student Facing

• Let’s try to multiply two-digit numbers with an algorithm that uses partial products.

### 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

How did understanding the cool-down of the lesson before you started teaching today help you synthesize that learning?

### Suggested Centers

• Five in a Row: Multiplication (3–5), Stage 3: Two-digit Factors (Addressing)
• Compare (1–5), Stage 3: Multiply within 100 (Supporting)

### Print Formatted Materials

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