Begründen Sie! Give reasons. Widerlegen Sie! Disprove it. Gibt es? Is there such a thing? Gilt das immer? Is that always true? The education ministers of the German states list these instructions as typical tasks in their national standards for the Abitur in mathematics, adopted on 18 October 2012. The standards make mathematical argument one of the core competences. The range runs from simple plausibility arguments to formal proofs. At the middle level, pupils must follow, explain or develop manageable arguments of several steps.