Math manipulative blocks for homeschooling or whatever, in the style of the Math-U-See manipulatives. These act as a physically movable visual aide for a young student to learn the basics of arithmetic.

A full set is 10 of each block.

The STLs uploaded here have a pretty tight tolerance to allow the blocks to press together solidly. If your printer has different tolerances than mine or you just want looser blocks that are easier for your kid to stack, open the SCAD file in OpenScad or the Customizer and increase the extra_negative_space parameter.