Johannes Widman attended the University of Leipzig graduating in 1482. His Master's Degree was awarded in 1485 and he then taught at the University of Leipzig on the fundamentals of arithmetic and algebra.
Widman's 1486 algebra lecture is the first given in Germany. He used Cossist notation as was usual at that time. He considered computation with irrational numbers and polynomials to be part of algebra.
Widman is best remembered for an early arithmetic book in German in 1489 which contains the first appearance of + and - signs. It is an early example of a printed arithmetic book and it is better than those before it in having more examples and a wider range of examples. His book was reprinted until 1526 when it was superseded by one by Adam Ries and others.
There are no direct references to Widman after 1489 but it is believed that he was still working on mathematical topics in 1498.