The abstract science of numbers, quantity, and space, either as abstract concepts in the form of pure mathematics, or as pertaining to other disciplines such as physics and engineering, in form of applied mathematics.
The branch of mathematics that deals with collection, analysis, interpretation, and presentation of numerical data.
The branch of mathematics concerned with the analysis of strategies for dealing with competitive situations where the outcome of a participant's choice of action depends critically on the actions of other participants.
Calculus is the branch of mathematics that concerns itself with continuous change.
Geometry is the branch of mathematics concerned with the properties and relations of points, lines, surfaces, solids, and higher dimensional analogues. Topology is the study of geometrical properties and spatial relations unaffected by the continuous change of shape or size of figures.
Pretty much anything else that is mathematical, but not covered by the other topics. Including Algebra, the branch of mathematics that deals with study of generalizations of arithmetic operations.