This is a Smart Notebook Lesson based on Eureka Math 3rd Grade Module 2 Lesson 14: Rounding to the Hundreds. I have taken parts of the lesson and incorporated them into this lesson. I have changed a few details such as the number lines to adapt to my teaching. The Eureka Math lesson uses vertical number lines. I find my students relate to the horizontal number lines better so that is what is in this lesson. Also, there is a link to a wonderful video on rounding on a number line and interactive practice included in this lesson. Even if you are not using Eureka Math, this lesson can be used because it is correlated to the Common Core for 3rd grade.