Rounding Lesson

Affiliate link ahead

Teaching rounding isn’t for the faint of heart. It involves a concrete understanding of place value, which many fourth grade students are still working on. Using manipulatives, number lines, and interactive notebooks can help your students visualize this difficult standard.

One of the [free] organizers I use to teach rounding uses number lines for rounding. I love teaching this lesson with number lines for several reasons:

  1. Students have used number lines before. This allows them to use this prior knowledge to learn how to use number lines with more complex numbers.
  2. Students can visually see which ten, hundred, or thousand the number is closest to.
  3. Breaking up the number line into fractional pieces is great practice for when we use number lines with fractions later in the year.

Click here for this free lesson!



Because I use this organizer in our interactive notebooks as my model, I already have the number lines pre-labeled for students. It makes it so much easier, especially for the students that struggle with note-taking.


We cut the number line into pieces (beginning with halves, then fourths). We then discuss where 146 goes on the number line. This number is 4 less than 150, so we plot it just a little bit before 150. Then we decide: Is 146 closest to 100 or 200? Students can visually see that it’s closer to 100.

We also discuss why the number line is drawn like this. If we’re looking for the closest hundred to 146, we have two options: 100 or 200. Those are our beginning and ending points on the number line.


We continue to practice rounding using different place value. I always use bright markers [I used these – affiliate link] so it’s easy for my students to see, but I have my students use colored pencils. Colored pencils are a staple in our group bins because we use them so much to color code our math in our interactive notebooks.


Once we’re finished with all of the examples, we glue the flap book into our interactive notebooks in our rounding section.


To download this flap book and another great rounding note page for your interactive notebooks, click here. This lesson is free!


After our number line note taking, we break out our base 10 blocks [aff. link] and do more rounding problems in our notebook. We use our base 10 blocks to “build” our number lines and assist in our rounding.

Thanks for reading and enjoy your free rounding resource!

Check out this hands-on number line manipulative!