What programming projects would help me practice calculus, statistics, and linear algebra?

A small physics simulation would be a great fit. You could use calculus for position, velocity, acceleration, and numerical integration; linear algebra for vectors, matrices, rotations, and coordinate transformations; and statistics to analyze the simulation’s results or compare different methods.

You could build your own small mathematics library and test it thoroughly. Implement functions such as sums, means, standard deviations, matrix operations, derivatives, and numerical integration, then write independent tests and compare the results against trusted examples or a scientific computing library.

A game could easily bring all three subjects together. For example, a 2D or 3D game might use linear algebra for movement and graphics, calculus for physics and motion, and statistics for balancing mechanics, analyzing player behavior, or tuning procedural systems.

Choose a problem that naturally uses one or more of the subjects and solve it in the programming language you prefer. Good options include projectile simulation, image transformations, regression, Monte Carlo experiments, neural-network basics, or an optimization problem. The important part is to explain the mathematics, implement the solution yourself, and investigate how accurate or efficient it is.