# Lesson 1 What is One Thousandth?

Let’s make sense of thousandths.

## Warm-up Estimation Exploration: One Tiny Piece

What fraction of the whole picture is a single square tile?

Record an estimate that is:

too low | about right | too high |
---|---|---|

## Activity 1 What Do You Know About Thousandths?

What do you know about 1 tenth?

What do you know about 1 hundredth?

What do you know about 1 thousandth?

## Activity 2 Represent Numbers on a Hundredths Grid

The grid represents 1. What does the shaded region represent?

Be prepared to explain your reasoning.

The grid represents 1. What does the shaded region represent?

Be prepared to explain your reasoning.

How many of the small rectangular pieces (one of them is shaded) are there in the unit square?

Explain or show your thinking.

How do you think we write the number one thousandth as a decimal? Explain your reasoning.

Fraction

Decimal

?

## Practice Problem

## Problem 1

What fraction of the whole square is shaded? Explain or show your reasoning.

What fraction of the whole square is shaded? Explain or show your reasoning.