# Exemplar: Place value and the "power" of ten

## About this lesson

**Lesson objective:** Understand that when digits in a multi-digit whole number shift to the right, the value is ten times less than the initial value.

**Math concept addressed:**

In this Guided Collaborative Task, students will use their knowledge and understanding of multiplying and dividing multiples of ten to figure out the value of a structure of base ten blocks that is ten times less than the initial value. Students will figure this out by building structures with base ten blocks and then building a value that is worth ten times less.

Under the “Additional materials” tab, you’ll find a place value mat that may be used as students organize their thinking about the place value concepts using base ten blocks or place value disks.

**Prior knowledge needed:**

Students bring prior knowledge of multiplying and dividing multiples of ten from 3.NBT.A.3. This prior knowledge is extended to recognize that when digits in a multi-digit whole number shift to the right, the value is ten times less than the initial value and when digits in a multi-digit whole number shift to the left, the value is ten times more than the initial value.

**How students will collaborate:**

Collaboration happens through the back to back collaborative structure.

**Mathematical practice featured:**

Students engage in Mathematical Practice 8 (Look for and express regularity in repeated reasoning) as they notice that each time you multiply by ten the digits shift to the left and each time you divide by ten the digits shift to the right

**Key vocabulary:**

- digit(s)

- ones

- place value

- tens

- ten thousands

- thousands

**Special materials needed:**

- base ten blocks

- place value disks (optional)

- place value mat (optional)