After mathematical analysis, you will learn real variable function and complex variable function first. Mathematical analysis usually takes three semesters. In the third semester, you will learn ordinary differential equations. After learning real and complex variables, you will learn functional analysis. Abstract algebra, discrete mathematics, numerical analysis and topology are not all required, and different mathematics majors need to learn differently. Algebra with real variables and complex variables is modern algebra. I will study topology, combinatorial mathematics and so on. Numerical analysis is a kind of computational science, and discrete mathematics and graph theory should be studied by mathematics students who are partial to computers.