Interactive Physical Number line

This is an object I'm certain can help many teachers when teaching math. It is a number line. It comes with one main body and two extensions on each side (you don't have to print them off), it also includes the attachments from 1-10 which you also can print off as many as you need. How to use it is in the instructions.

When I was a kid I always had trouble with grasping the concept of integers. I couldn't understand that you could take away ten from two. And no matter how hard my teacher tried she couldn't get the majority of the class to comprehend subtracting negative numbers let alone multiplying and dividing. That is until our teacher started using number lines. A number line can be used by all math students. To young kids it teaches addition and subtraction; to slightly older kids it can teach multiplication and division; and finally to more advanced kids it can teach adding, subtracting, multiplying and dividing integers. I believe this tool will help teachers substantially a