In previous lessons, students learned to compare three-digit numbers using the value of each digit. They used the number line and base-ten diagrams to compare numbers and explain their thinking.

The purpose of this lesson is for students to compare three-digit numbers and place them in order from least to greatest and from greatest to least. Throughout the lesson, students are encouraged to use their understanding of place value to reason about the correct order of a set of numbers. They also use the number line as a tool for sequencing numbers and visualizing the relative distance between numbers. The work of this lesson helps students consolidate their understanding of the counting sequence, the base-ten structure of numbers, and the relative position of numbers on the number line. These understandings will be helpful as students add and subtract within 1,000 in future lessons.

In future lessons, students will add and subtract within 1,000. How does the work of this unit prepare them for that work? How can centers be used to strengthen students’ understanding of place value?