The purpose of this study was to investigate how high school mathematics teachers' descriptions of academic optimism, responsive teaching, technological pedagogical content knowledge, formative assessment, reflective practice, supervisor instructional leadership, and receptivity to change are related to student mastery on a NYS Regents exam in mathematics in low need and high need suburban school districts in New York State. A survey was completed by 132 teachers from low and high mastery high schools within New York State. Math mastery was measured with a 3-year average of the percent of students scoring at level 4 in mathematics after 4 years of instruction. Three-year average of the percent of students eligible for free lunch from the New York State Comprehensive Report Cards was used to determine need level. The data revealed that reflective practice was the strongest predictor for placement in low or high mastery schools. Academic optimism was a predictor for placement in low or high need schools. Teachers need to possess academic optimism and receptivity to change. These qualifies were correlated to other variables that. demonstrated gains in academic achievement. Overall, teachers from all schools reported low levels of receptivity to change and instructional leadership. Teachers from schools with high mastery tended to report higher levels of technological pedagogical content knowledge. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]