Unit 4, Lesson 4
Standard Algorithm: One-digit and Multi-digit Numbers, with Composing
Grade 5
Preparation
Lesson Narrative
In IM Grade 4, students interpreted the standard algorithm for multiplication and compared it to a partial-products algorithm to multiply up to four-digit numbers by one-digit numbers. In this lesson, students extend their understanding of the standard algorithm to multiply up to five-digit numbers by one-digit numbers, including problems in which one or more new units are composed. This is the first in a series of lessons to support students in developing fluency in using the standard algorithm to multiply multi-digit numbers.
- Representation
None
- Calculate the product of a one-digit number and a multi-digit number, using the standard algorithm.
- Interpret (orally and in writing) the steps in a worked example, calculating the product of a one-digit number and a multi-digit number, and critique (orally) an interpretation.
- Let’s use the standard algorithm to multiply multi-digit numbers by one-digit numbers.
Required Preparation
None
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?