Mathematics is a fundamental field of study that plays a pivotal role in the development of science, technology, business, and computer science. It profoundly influences the socio- Economic development of a society and civilization. Thus, it is imperative that students be Equipped with strong Mathematical knowledge and skills which enable them to be productive in areas where rigorous thought and precision of results are emphasized. Preparing this mathematics teaching material for Grades 11 and 12, in STEM Project, aimed at inspiring and encouraging the students for further investigation in mathematics. Research findings indicate that addressing problem solving and proving activities each day in the class would affect the thinking and reasoning skills of the students. We discovered that the students became more adept at mathematics problem solving and proving mathematical statements as they practiced various types of mathematical problems and mathematical statements. The target groups are Grades 11 and 12 students.