Experiment with tessellation using this easy to customise OpenSCAD script. Print out some triangles, squares, pentagons and hexagons and see which ones can tesselate and which can't. Penrose tiles are included too.
Print the last layer in a different colour to get coloured outlines which give a clearer pattern when tiling shapes of the same colour. Or use a permanent marker to add colour after printing.
You'll have just as much fun playing with them as your children will.
For using with younger kids I'd suggest scaling the STL files by 200%.
The author hasn't provided the model origin yet.