Watch step-by-step instructions to make parts and assemble the Tech-Explorer catapult project developed by the Sierra STEM Community Collaborative at Sierra College (sierraschoolworks.com) in Rocklin, CA through the Center for Applied Competitive Technologies (CACT). High school students make this catapult with hand and power tools such as mills and lathes, and apply fractions, geometry and other math essentials. Through the applied academic experience, students' math skills are reinforced and careers in Science Technology, Engineering & Math (STEM) are introduced. This project is also used in the National Science Foundation Tech-Explorer project that further integrates math skills.