Jill Cheeseman and Deborah Michels let us eavesdrop on a young child's attempt to solve a four-digit subtraction. In the process they describe the use of an empty number line as a tool for describing the calculation process. If you haven't tried using an empty number line, then the authors outline some compelling reasons for using empty number…

Students in a college introductory statistics class were evaluated with conceptual and computational tests and the relationship between their levels of knowledge on the two forms of testing was assessed. There were significant correlations between their abilities to perform computations and to answer more conceptual questions on individual tests…