The present paper describes the success, the methods (mental, informal written, standard algorithm) and the strategies of informal written arithmetic to be observed when 300 elementary students worked ...

This study examined children's justifications and evaluations of derived-fact strategies-strategies for solving addition and subtraction problems by using known combinations-to explore their knowledge ...

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 ...