It seems there are two schools of thought when it comes to teaching students to round numbers. When you search "rounding anchor charts" on Pinterest, a whole slew of cute little rhymes about "going next door" to the neighboring number appear. You can also find a plethora of images with a rounding roller coaster (which is what I used to teach rounding to my second graders long ago during my first two years of teaching).
Recently, though, I ran across a blog post by Beyond Traditional Math that made me rethink my approach to teaching students how to round numbers. In fact, the author convinced me that teaching students to use number lines to round numbers is the best approach for most children because it provides the necessary conceptual understanding to support long-term retention. Tricks are too easily forgotten, whereas the number line approach supports number sense and place value understanding. (Read the blog post HERE.)
Therefore, when I decided to create a Rounding PowerPoint last week, I used number lines. However, in an effort to make things just a bit more engaging, I added ninjas! These two posters (which can be downloaded by clicking on the images) and the anchor chart show the basic premise.
If you are interested in possibly using this approach to teach rounding this year, feel free to check out my rounding ninja resources. All of these rounding activities address rounding 2-, 3-, 4-, and 5-digit numbers to the nearest ten, hundred, and thousand.
~Deb