Many mathematicians have been notable not just for their contributions to mathematics, but also for helping teach the next generation of mathematicians. A number of important mathematicians have tutored and helped other important mathematicians progress in their careers. Here are a few such mathematicians. Paul Erdős - Paul Erdős was a notable mathematician who lived an eccentric and mathematically productive lifestyle. He was known for collaborating with many other mathematicians, so many that his collaborating spawned the concept of the Erdős number, which measures how far away mathematicians are from citing some of Erdős's work. Erdős also influenced younger mathematicians, such as the Fields Medalist Terence Tao. Ernst Kummer - Ernst Kummer was a notable mathematician who made important contributions to mathematics in fields such as geometry and number theory. He also helped educate people in mathematics, one example being that he trained german officers in ballistics...