Reported are results from a pilot study evaluating the effectiveness of a high school mathematics course on the applications of proportional calculations for students subsequently enrolled in chemistry. Two effects were investigated: (1) the effect of the course on students' ability to do proportional calculations not explicitly involving chemical concepts and terms, and (2) the effect on students' performance in a regular secondary school chemistry course. Also investigated was whether there is a relationship between ability to do proportional calculations and Piagetian cognitive level. Results indicate that the course was effective in increasing students' ability to solve everyday problems, but that there was no difference in problem-solving ability of students who had taken the course. Results of the Piagetian investigation indicate that students can be taught to solve both concrete and formal proportional calculations independent of their cognitive level when the variables are familiar to the students. (CS)