The Royal Dutch Mathematical Society (KWG) organizes a number of annual activities, such as the Netherlands Mathematical Congress and the Winter Symposium. In addition to various symposia, the KWG also supports the annual Study Group Mathematics with Industry. The KWG is also involved in incidental seminars, such as in 2016, in the context of the Brouwer Year.
The Netherlands Mathematical Congress (NMC) is the annual congress of the KWG that brings together a few hundreds of researchers, students, teachers and others who acknowledge the importance and beauty of mathematics. Almost all lectures are in English. Once every three years at the NMC, the KWG awards the Brouwer Medal to a leading mathematician. See the NMC website.
Each year, in January, KWG organizes the Winter Symposium, mainly directed towards mathematics teachers in secondary education.