Research on the use of calculators in mathematics classes is reviewed. It is noted that calculators were initially too high-priced and of too low an availability to be viewed in terms of widespread use in classrooms. Technological and manufacturing advances have since made wide use possible. Proponents of calculator use see this technology as a learning aid that has the potential to increase student motivation levels and improve mathematics achievement. Some opponents are concerned that too early an introduction to calculators could keep pupils from learning and understanding some basic mathematical skills. Findings from many studies reflecting aspects of calculator usage are presented. The document concludes by noting that while the controversy over calculator use will continue, some generally accepted conclusions seem to exist. Among these is the idea that calculator use in mathematics classes prior to the junior high school level is ill-advised, since pupils in this group are still learning basic skills. Second, use of calculators by students of below-average ability appears ill-advised. Finally, it appears calculator use does aid pupils in logically planning approaches to problem solutions. (MP)