Hans Freudenthal (17 September 1905 - 13 October 1990) was born in 1905 in the German town of Luckenwalde, the son of a Jewish teacher. Even at a young age he was interested in differential equations and integration, but by the age of 13 he had also read all the works of Goethe and Schiller. In 1923 he went to Berlin and Paris to study mathematics. After gaining his doctorate he moved to Amsterdam, in the Netherlands, where he became assistant to L.E.J. Brouwer, the famous mathematician, in 1930. Shortly after, he married Suus Lutter, who was a pedagogue. Thanks to his marriage to a non-Jewish Dutchwoman and a certain amount of luck, Freudenthal was able to survive the Second World War. In 1946 Freudenthal became a professor in Utrecht, appointed to a chair in pure and applied mathematics and the principles of mathematics.
In his time Freudenthal was an accomplished and well-known mathematician, and he made substantial contributions to topology, geometry and the theory of Lie groups.As a teacher he acquired international fame and significance as the founder of realistic mathematics education, which is based on problems taken from day-to-day experiences rather than on abstract math rules. Single-handedly Freudenthal saved Dutch education from the American teaching method of New Math, which was introduced in many countries from 1960 onwards. This formal, logic-based method turned out to be unsuitable for most students.
Freudenthal preferred to send his students on a tour of discovery. His motto was that you learn mathematics best by re-inventing it. His students were not given abstract bare problems to do but well chosen practical problems from daily life, and in solving these they gradually developed mathematical understanding. In addition, Freudenthal thought the recognizability of the problems would lead to the students automatically becoming more interested in mathematics.
He served as the 8th president of the International Commission on Mathematical Instruction from 1967 to 1970. In 1971 he founded the Institute for the Development of Mathematical Education (IOWO) at Utrecht University, which after his death was renamed the Freudenthal Institute, and is now the Freudenthal Institute for Science and Mathematics Education. In 1972 he founded and became editor-in-chief of the journal Geometriae Dedicata. He retired from his professorship in 1975 and from his journal editorship in 1981.
More details can be found here:http://www.fisme.science.uu.nl/fisme/en/organisation/freudenthal.html and here: www-groups.dcs.st-and.ac.uk/%7Ehistory/Biographies/Freudenthal.html