These are copies of materials used in a Montessori classroom.
The 100 board is a square frame with 100 tiles, marked with all the numbers from 1-100. The child puts the numbers in order into the frame.
The teens board has 9 tens and uses the 1-9 tiles to make all of the teens numbers (plus 11 and 12.) The child makes all the teens, then places a 10 and a number bead next to each teen.
The tens board is similar. The number tiles are used to create sample numbers like "68" and the child then places 6 tens bars and 8 unit beads next to the number.
Note that there are fake wooden "beads" included, but you can delete them to reduce making costs.
This set looks good in clear color acrylics, and 5-ply 2.7mm bamboo blonde (the amber bamboo warps a bit.) It might also be fun in felt or leather.
Note that the number font used for the tens and teens boards is a font I built to look like the old timey Montessori numbers on the Stamp Game, etc. If you're interested in it, drop me a line. Also note that measurements are in metric -- standard Montessori practice, so children get familiar with common metric sizes.