The common-core math standards require that students learn the standard algorithm for multi-digit adding and subtracting—you know, the process in which you line the numbers up vertically to add or ...

Your child continues to use tape diagrams as a visual tool to solve word problems. Your child continues to use tape diagrams as a visual tool to solve word problems. Now, he solves for an unknown in ...

Students put all of their addition and subtraction skills together to solve equations. In this lesson, students put all of their addition and subtraction skills together to solve equations. Julia ...

A thorough understanding of addition and subtraction requires knowledge of the inverse relation between these operations. According to Piaget (1952), any inverse relation poses a significant challenge ...