Lesson 5-- Rounding to the Nearest 100 Using a Number Line

Introduction

Hello Mathematicians! Today we will continue to work on how to round numbers to the nearest hundred. We will learn how to use number lines to do this.

Video

Interactive

Directions:

In the interactive, round each number to the nearest hundred.
In your notebook, show on a number line:
- the hundred before and the hundred after the number,
- the midpoint between the hundreds,
- the number,
- and which hundred the number rounds to

In Your Math Notebook:

Let’s get out our math journals and work through the following application problem. Make sure you read the problem carefully, draw a picture to match your thinking and write and solve an equation. Remember sometimes we don’t need an exact answer. Look for key works like “about how many” to help you know when an estimate is expected to be given.

**Read, Draw, Write. DONE!**
R (Read the problem carefully.) Leo is saving money to buy a new gaming system. The gaming system costs $386. He also wants to buy a video game that costs $65. a. Leo is estimating the amount of money he should save to buy the gaming system and video game. Should Leo round to the nearest ten or the nearest hundred? Explain your reasoning. b. About how much money does Leo need to save to buy the gaming system and the video game? D (Draw a picture.) W (Write and solve an equation.)

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Georgia Department of Education, Math