# Lesson 6

Standard Algorithm: Multi-digit Numbers with Composing

### Lesson Purpose

The purpose of this lesson is for students to understand and apply the standard algorithm for multiplication when multiplying two- and three-digit numbers with composition of new units.

### Lesson Narrative

In previous lessons, students learned to use the standard algorithm for multiplication with up to five-digit numbers and one-digit numbers when a new unit is composed. They also multiplied three-digit and two-digit numbers without composing a new unit. In this lesson, students combine these two skills. They use the standard algorithm for multiplication of a three-digit and a two-digit number and record the composition of new units.

- Engagement

- MLR8

Activity 1: Compose a New Unit

### Learning Goals

Teacher Facing

- Use the standard algorithm to multiply up to three-digit numbers and two-digit numbers, including composing new units.

### Student Facing

- Let’s multiply with the standard algorithm and compose new units.

### 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

As students worked in their small groups today, whose ideas were heard, valued, and accepted? How can you adjust the group structure tomorrow to ensure each student’s ideas are a part of the collective learning?

### Suggested Centers

- Number Puzzles: Multiplication and Division (4–5), Stage 2: Multi-digit Factors (Addressing)