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.
Required Preparation
CCSS Standards
Addressing
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)