The Application units plunge students into an extended role-play as employees involved in a real-world design problem: creating codes, designing floor plans, making maps, or building biological models. A series of memos structure students design work from initial research to design to analysis to communicating their results. Accompanying software applications provide easy-to-use tools for exploring the real-world context as well as demanding the use of mathematics to solve the problem. Mathematical concepts and skills are integrated within the project work and are progressively developed throughout the unit. In the form of teacher notes and student handouts, specially designed math activities direct students' project investigations in particular ways, highlight and name the mathematics students are using, and in other ways support students' learning new mathematics in the context of the application problem. Each unit introduces and uses at least two new mathematical concepts along with several minor math themes and opportunities to practice skills. Assessment materials and tips are integrated into each unit.