These can be made into more shapes and sculptures than you might think. Fun for kids of all ages, and adults too!
Designed in Tinkercad (https://tinkercad.com/things/l5uepbEdIW4). I designed these fit onto a 149x149mm build plate, leaving 5mm at the edges. My print ended up going out to the bolt holes on a Replicator. :)
The smallest block doesn't print very well (there's an empty space under the lettering which needs a fix).
The pictured pieces were printed at 5% infill, 0.34mm layer height, 1 shell. Next time I'd add a shell and use 10% infill.