The purpose of this research is to explore how a method course improves prospective elementary teachers’ knowledge of various structures of addition and subtraction word problems. For this purpose, 55 prospective elementary teachers who were enrolled in a mathematics education method course were asked to pose addition and subtraction word problems before and after completion of the specific unit called “Developing Meanings for the Operations”. Problems created by participants were then analyzed and categorized in light of the theoretical frame. Repeated measure design as one of the quasi-experimental designs was used in this study to measure the effects of the instruction over time. One-way ANOVA techniques were applied for data analysis. The findings of this study suggested that although certain types of problems are extensively created by participants before starting the unit, participants created more diverse addition and subtraction word problems upon completion of the specific unit.