Lesson objective: Students will practice representing numbers as lengths on a number line.

This lesson helps to build procedural skill with representing lengths on a number line. A number line diagram is used here because it provides a continuous representation for counting in order, helping students understand relationships between counting on with adding, and counting back with subtracting. This work develops students' understanding that we can represent whole numbers as lengths from zero on a number line diagram with equally spaced points corresponding to the numbers.

Students engage in Mathematical Practice 6 (Attend to precision) as they represent whole numbers as lengths on the number line. They label the number lines precisely and are careful to keep intervals between labels equally spaced.

**Key vocabulary:**

- number line diagram

**Special materials needed:**

- empty number lines (optional)