keywords: partial sums, column addition, expand-and-trade subtraction, counting-up subtraction, rounding, estimates, addition, subtraction, algorithms, Everyday MathDo your students struggle to successfully execute the many steps required to solve a addition and subtraction problems using the alternative algorithms taught in Everyday Mathematics? These wipe on/wipe off boards are exactly what you need. Just add page protectors and dry erase markers and your students will be adding and subtracti