Brutkey

Wynke
@wynke@mendeddrum.org

@ColinTheMathmo@mathstodon.xyz @MathsJam@mathstodon.xyz @BigMathsJam@mathstodon.xyz I arrived home since and have found it. It's part of the 'Zebra-reeks', which is a Dutch series of mathematical materials that aren't part of the standard curriculum, aimed at the final years of the highest level of high school (pre-university) in the Netherlands.

More about the Zebra-reeks:
https://www.epsilon-uitgaven.nl/zebra-reeks