# Lesson 4

Standard Algorithm: One-digit and Multi-digit Numbers with Composing

### Lesson Purpose

The purpose of this lesson is for students to use the standard algorithm to multiply up to five-digit numbers and one-digit numbers.

### Lesson Narrative

In grade 4, students interpreted the standard algorithm for multiplication and compared it to a partial products algorithm to multiply up to four-digit numbers and one-digit numbers. In this lesson, students extend their understanding of the standard algorithm to multiply up to five-digit numbers and one-digit numbers, including problems where one or more new units are composed. This is the first in a series of lessons to support students in developing fluency using the standard algorithm to multiply multi-digit numbers.

- Representation

### Learning Goals

Teacher Facing

- Use the standard algorithm to multiply up to five-digit numbers by one-digit factors, including composing new units.

### Student Facing

- Let’s use the standard algorithm to multiply one-digit numbers and multi-digit numbers.

### Required Preparation

### CCSS Standards

Addressing

### Lesson Timeline

Warm-up | 10 min |

Activity 1 | 20 min |

Activity 2 | 15 min |

Lesson Synthesis | 10 min |

Cool-down | 5 min |

### Teacher Reflection Questions

What evidence do you see that your students are applying what they learned about partial products to make sense of the standard algorithm?

### Suggested Centers

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