Provided is a teacher's guide for a problem-solving activity that establishes a link between number patterns and geometry by focusing on the development of recurrence relations established when generating central polygonal numbers. Reproducible worksheets and a 3.0 BASIC program for the activity are given. (MDH)

During a six-week methods course for preservice elementary school teachers, student pairs were asked to solve a problem and record their experiences in a dairy. Presented are the dairy entries of two students as they worked on determining the number of squares that can be formed on a five-peg geoboard. (MDH)

Elaborates the final step of Polya's heuristic model, reflecting, to improve students' problem-solving performance. After checking answers for accuracy, the following steps are suggested: (1) test reasonableness and practicality; (2) write a summary paragraph; (3) find other solutions; (4) change the conditions; and (5) extend the problem. (MKR)