I am excited to bring to you this free version of the ZeroSum Ruler’s eBook! In this book, you will find pictures and explanations of how the ZeroSum Ruler is different yet more intuitive in its way of teaching integer addition and subtraction. if you like what you read, there is a version of the eBook on CurrClick that includes a ZeroSum Ruler, practice problems, and some more fin pictures. Enjoy! (click the picture below to be directed to your free download!)
If you need convincing to download this eBook for free (??), you should go to the GRADUATE THESIS tab (up there) to read how the ZeroSum Ruler decreased student error by 62%!