|digits making up |
the base ten number system.
Modern mathematics is normally built around base 10, with ten digits. () Modern mathematics is separated into two categories: discrete mathematics and non-discrete.
Non-discrete mathematics is study of mathematics that is generally applicable to the "real world", such as algebra, Euclidean geometry, statistics, and other such topics. (Note that the real world is actually only approximately Euclidean if one studies large areas of it, infinitesimal areas actually are non-Euclidean) There is some controversy over what varieties of algebra are non-discrete, but it is generally agreed that elementary and superior algebra are non-discrete, while abstract algebra and intermediate topics such as field and graph theory and Diophantine equations are discrete.
Combinatorics, number theory, and some of the algebraic fields mentioned above are examples of discrete mathematics. Topics of discrete mathematics are generally not directly applicable to the "real world", and if they are, it is only in an abstract fashion.