# arithmetic

The branch of mathematics concerned with addition, subtraction, multiplication, and division of numbers.

All elementary arithmetic is based on counting. Addition is generalized counting (which is why people often add by counting on their fingers) and multiplication is repeated addition. Subtraction and division are inverses of these operations.

In modern mathematics arithmetic is formalized in the Peano axioms.

- Smith, B. Sidney: author

- [MLA] Smith, B. Sidney. "arithmetic."
*Platonic Realms Interactive Mathematics Encyclopedia.*Platonic Realms, 21 Feb 2013. Web. 21 Feb 2013. <http://platonicrealms.com/> - [APA] Smith, B. Sidney (21 Feb 2013). arithmetic. Retrieved 21 Feb 2013 from the
*Platonic Realms Interactive Mathematics Encyclopedia:*http://platonicrealms.com/encyclopedia/arithmetic/