Pythagoras is considered to be the first real mathematician. As an extremely important Greek philosopher and mathematician and founder of the Pythagorean School, but very few information is known about him and his life. The Pythagorean view of the world consisted of a belief that numbers were the keys to the various qualities of mankind and matter. In the Pythagorean view, everything was composed of numbers, the explanation for any objects existence could only be found in numbers. This was a completely novel concept, because at that time, numbers existed for practical purposes only, as a device for solving problems in calendar construction, building and commerce. Pythagoreans were the first who saw a number as an idea, important in itself.