* Elective course 3- 1: Selected lectures on the history of mathematics; * Elective course 3-2: Information Security and Password; * Elective course 3-3: Geometry on Sphere; * Elective 3-4: Symmetry and Group; * Elective course 3-5: Euler Formula and Classification of Closed Surfaces; * Elective course 3-6: Angle trisection and number field expansion.
* Elective course 4- 1: Selected lecture on geometric proof; Elective 4-2: Matrix and Transformation; * Elective Course 4-3: Order and Difference; Elective 4-4: Coordinate System and Parameter Equation; Elective 4-5: Selected lectures on inequality; * Elective Course 4-6: Elementary Number Theory; * Elective Course 4-7: Optimization Method and Preliminary Experimental Design; * Elective 4-8: Overall Planning and Graph Theory; * Elective 4-9: Risk and Decision-making; * Elective course 4- 10: Switching Circuit and Boolean Algebra.