18.2x and 18.3x
Applied Mathematics
This heading includes discrete applied mathematics (18.2x), including Combinatorics, as well as continuous applied mathematics (18.3x). The gateway subjects to these two areas are:

18.200 (Principles of Discrete Applied Mathematics) develops the principles of discrete applied mathematics. It carries CIM credit. Prerequisites: 18.02. The variant, 18.200A, covers the same material as 18.200, except for the communicationintensive component and does not give CIM credit.

18.300 (Principles of Continuum Applied Mathematics) develops the principles of continuous applied mathematics. Prerequisites: 18.02 and 18.03.
Other basic subjects include:

18.211 (Combinatorial Analysis) is a foundational subject in combinatorics. Prerequisites: 18.02 and Linear Algebra.

18.303 (Linear Partial Differential Equations) develops the classical partial differential equations of applied mathematics. Prerequisite: Linear Algebra.

18.330 (Introduction to Numerical Analysis) develops the foundations of numerical analysis. Prerequisites: 18.02 and 18.03.
Further applied mathematics subjects, requiring somewhat more background, include:

18.212 (Algebraic Combinatorics) a more algebraically demanding approach to combinatorics than 18.211. Prerequisites: 18.701 or 18.703.

18.353J (Nonlinear Dynamics: Chaos) coincides with 2.050J and with 12.006J. Prerequisites: 18.03 and 8.02.

18.354J (Nonlinear Dynamics: Continuum Systems) coincides with 1.062J and 12.207J, and serves as a partner to 18.353. Prerequisites: 18.03 and 8.02.
There are two Undergraduate Seminars in applied mathematics:

18.204 (Undergraduate Seminar in Discrete Mathematics) Prerequisites: 18.200 or 18.062; and Linear Algebra.

18.384 (Undergraduate Seminar in Physical Mathematics) focusing on continuous applied mathematics. Prerequisites: 18.300 or 18.353 or 18.354.