This idea is so simple and quick we would like to share it with all teachers (and IKEA-hackers alike).
Looking for a proper way to attach magnetboards in the classroom at the height of our 4-5 year olds, we discovered that the IKEA SPONTAN spontaneously fits snug in the sidepanel of our common mobile cabinets (schilte).
No screws, no glue, just click.
If you want to remove them, use a screwdriver to flip them out.
~ Team De Bolster