Lesson objective: Represent three-digit numbers using word form.

This lesson helps to build procedural skills with writing three-digit numbers in word form. Base ten blocks and expanded notation are used here because they support understanding of the value of each digit in a number. This work develops students' understanding that there are a variety of equivalent ways to represent a number.

Students engage in Mathematical Practice 7 (Look for and make use of structure) as they rely on place value patterns to write numbers in word form.

**Key vocabulary:**

- expanded form
- hundreds
- ones
- tens
- value
- word form

**Special materials needed:**

- base ten blocks
- place value mat (optional)