Summary

Base 10 Cubes are used in elementary schools to teach base-10 numbers. The usual set is 10 ones (which stack to make a 10-rod), ten 10-rods (which stack to make a 100-square), and 10 100-squares to stack to make a thousand-cube. Use your slicer to build the
pieces you need.

This version includes STL files for each individual part, as well as
an OpenSCAD file to produce them all (comment in or out the
parts you want). These are 12mm cubes, which is a compromise
between size and speed/material consumed. Note that the
"size" gets expanded by the rounding sphere radius * 2, so if you
change the OpenSCAD file, be aware of that.