An intensive, friendly and exceptionally productive cooperation with Markus Hohenwarter, the ingenious developer of GeoGebra, in the years 2004 to 2011 was very important and extremely profitable for both the development of realmath.de and GeoGebra. Looking back, one can rightly speak of a perfect win-win situation.
This will be described here in the form of highlights.
Markus Hohenwarter develops GeoGebra in the context of his doctoral thesis at the University of Salzburg. During this time I created dynamic drawings on realmath.de with the dynamic software EUKLID-DynaGeo. One day Markus Hohenwarter contacted me by e-mail and asked if I would like to use his java-based software GeoGebra for the dynamic drawings on realmath.de. I declined, because at that time GeoGebra could not be operated via button input but only awkwardly via commands. Three days later the new control for GeoGebra, as it is known today, was ready. Impressive speed!
What started now, I would like to call a ping-pong effect. This manifested itself in the fact that I maintained my rejection for GeoGebra and always pointed out programming backlogs. These were repaired by Markus in shortest time, but I referred again to further construction sites. Here a small excerpt:
I reminded that e.g. lengths of distances or the notation of vectors could not be integrated into the drawing in the form used in school. Within shortest time Markus programmed this application. The forefather of the latex connection was born.
I pointed out that teachers for the use of dynamic software attach great importance to a scaled printout. Better yet an output to the clipboard from which the drawing can then be integrated into any word processing program. From my previous conversations with java program developers, I knew that this would probably not be possible. But Markus had a brilliant idea here, too. He programmed an export via images in png format, like you can still find in GeoGebra today.
October 4 - 6, 2006: Conference of the seminar teachers for mathematics at Bavarian secondary schools in Dillingen, lecture on GeoGebra and workshop on interactive dynamic worksheets with realmath.de.
Looking back, this event can be confidently called the starting signal for the use of GeoGebra at Bavarian schools. The lecture and workshop with GeoGebra was a terrific success for GeoGebra. The enthusiasm of my former seminar teacher colleagues was extraordinary. Finally an application that meets all school requirements. So the program of the conference was changed at short notice and I was asked to hold another workshop with the in-depth use of GeoGebra. From then on, the seminar teachers acted as multipliers.
During this time I developed numerous worksheets that made the possibilities of GeoGebra visible to developers. These could be made available to interested developers on the GeoGebra Wiki. Gradually, hundreds of worksheets were created with content on nearly every topic in secondary school mathematics. Many materials that can be found on GeoGebra today are based on ideas from my dynamic drawings. One only needs to look at the drawings for illustration in fractions on realmath.de and GeoGebra.
During these years, I was often asked to be a speaker for internal, regional, but also supra-regional teacher training courses. Due to the high quality and extensive further developments at GeoGebra, these were very successful. A small excerpt ...
Since my appointment as headmaster of the state secondary school in Vohenstrauß in 2012, the extremely intensive and excellent cooperation has been suspended due to time constraints.