ABSTRACT
Chapter 8 focuses on the cross-products procedure, which is often poorly understood by students and often considered a trick. In addition, premature introduction or limiting students to only using the cross-products procedure may interfere with developing proportional reasoning. Regardless, the cross-products procedure is an efficient proportional strategy that is based on sound mathematical understanding. It is not a question of if students should be introduced to the cross-products procedure but when in their experience with ratios and proportions is the optimal time so that its use does not interfere with the development of ratio and proportion concepts.
