This course can also be taken for academic credit as ECEA xxxx, part of CU Boulder’s Master of Science in Electrical Engineering degree. This course teaches commonly used approximation methods in quantum mechanics. They include time-independent perturbation theory, time-dependent perturbation theory, tight binding method, variational method and the use of finite basis set. In each case, a specific example is given to clearly show how the method works. At the end of this course learners will be able to: 1. use time-dependent perturbation theory to obtain first- and second -order corrections to energies and wavefunctions, 2. use time-dependent perturbation theory and obtain transition rates, and 3. use tight binding method, variational method and finite basis set to obtain approximate solutions of various quantum mechanics problems.