Start with high-confidence applied math books, then narrow by subgenre or adjacent topics.
Linear Algebra and Its Applications
Gilbert Strang
Concrete Mathematics
Ronald L. Graham, Donald E. Knuth
Street-fighting Mathematics
Sanjoy Mahajan, Carver A. Mead
Mathematical Modeling in Systems Biology
Brian P. Ingalls
Compatible Spatial Discretizations
Douglas N. Arnold, Pavel B. Bochev
Mathematics for Physical Chemistry
Robert G. Mortimer, S.M. Blinder
Partial Differential Equations
Walter A. Strauss
Linear Algebra for Dummies
Mary Jane Sterling
Elementary Linear Algebra
Howard Anton
Technical Math for Dummies
Barry Schoenborn, Bradley Simkins
Fabulous Fibonacci Numbers
Alfred S. Posamentier, Ingmar Lehmann
Mathematical Modelling of Biosystems
Rubem P. Mondaini, Panos M. Pardalos
