Mathematics branches out over many different subject areas. If you want to browse either the reference (main floor) or regular (upstairs) collections to find material, I would suggest that you look in the following sections:
QA 1-43 - General Mathematics
QA 47-59 - Tables
QA 71-90 - Instruments and Machines
QA 101-145 - Elementary Mathematics. Arithmetic
QA 150-272.5 - Algebra
QA 299.6-433 - Analysis
QA 440-699 - Geometry. Trigonometry. Topology
QA 801-939 - Analytic Mechanics