Accessible Standard Algorithms for Understanding and Equity: Multidigit and Decimal Subtraction, Multiplication, and Division

A standard algorithm uses single-digit operations and concepts of place value (Fuson & Beckmann, 2012/2013; The Common Core Writing Team, 6 March 2015). We clarify in this paper that there are several standard algorithms for each kind of multidigit computation and summarize criteria for choosing better algorithms to teach. We discuss the better standard algorithms for multidigit and decimal subtraction, multiplication, and division that we have found to be accessible to students and to parents in our years of work across many schools across the United States. By accessible we mean that students can understand, explain, and carry out accurately the written methods. We teach students to make math drawings that facilitate their understanding by relating each step in the drawing to each step in the written accessible standard algorithm.