Take a Guess... What readily available tool is the most UNDER-utilized mathematical tool in most classrooms? Did you guess the number line? If you did, you would be correct! In our school district, a number line is one of the requirements for every mathematics classroom. In most classrooms, however, it hangs above the SmartBoard (often too high for our little learners or even for the teacher to access!) and, on most days, does little more than decorate the wall. Let's bring the number line to life! Cara and I created a 20-minute video that shows you 12 ways that you can use an Open Number Line in your classroom to help your students build greater Number Sense. VIDEO LINK: Click HERE to view the video: Using an Open Number Line to Develop Number Sense ACTIVITY DIRECTIONS: Click HERE for a .pdf file of written directions for each activity shown in the video NUMBER LINE MARKER CARDS: Click HERE for a copy of the number markers used for these activities - Tip: Use paper from the recycle bin. Cut the paper into strips and make number tents like the ones shown above. I find that it is actually easier this way since you don't have to hunt for the right card each time.