The ultimate goal of high school mathematics teachers is to create a meaningful learning environment that is conducive to teaching students the necessary concepts for academic achievement. Unfortunately, evidence suggests that many secondary educators still teach in a rote lecture style that focuses on the teacher providing information to passive, uninvolved students. Current mathematics reform movements endorse inquiry-based, "guide on the side" instruction grounded in constructivist pedagogy. The authors' research examines the effects of constructivist teaching and learning in pre-service secondary mathematics courses. The applicability of constructivism to teach secondary mathematical concepts, using practical instructional ideas, will conclude the article.