They used a base 10 system.

Pythagoras founded a philosophical and religious school in Crotone.Much of the early Greek arithmetic and geometry can be traced to Pythagoras.

Hypsicles of Alexandria named the 360 parts of a circle degrees when he divided the zodiac.

In his work, Geminus redefines parallel lines and gives an ingenuous but false proof for the parallel postulate. his inaccuracy was that he assumed that something could be proved without a postulate.

Johannes Widman wrote a book in 1489 that uses the + and - signs

Newton publishes The Mathematical Principles of Natural Philosophy.Its considered to be one of the most important single works in the history of modern science. This work contains Newton's version of the Calculus.

It was proposed in 1924 that gold medals should be awarded to recognize outstanding achievement. It wasn't until 1936 that the medals were first awarded to Ahlfors and Douglass. The Fields Medal is equivalent to the Nobel Prize.

Ken Appel and Wolfang Haken showed the four color conjecture was true using 1200 hours of computer time to examine 1500 configurations. The theorem states that any map in a plane can be colored using four colors in such a way that regions sharing a common boundary (other than a single point) do not share he same color