We have just introduced it in our home, and it was a big success.
Here is a video of how to use the board that I found quite useful:
My DIY version is made using very simple materials, namely felt and adhesive felt, also known as presto felt.
I bough mine at Joanne's but I am sure Michaels and other crafts stores have it too.They come in individual 8" x 11" sheets, so you can buy exactly what you need for a few dollars.
Basically I cut a 22" by 11" rectangle of blue felt, which doubles as a base and the blue squares in the board. After that I cut 12 green squares and 12 red squares, all measuring 2 1/4" x 2 1/4" in presto felt.
Using a picture as a model, I simply stuck them in order. Although not absolutely necessary, I use think strips of black presto felt to make a border around the board. Finally, I wrote the numbers corresponding to each column and row with a Sharpie.
Here is a graphic representation of how the board should look like:
This is our version:
As you have probably noticed, my beads do not follow the same color code as the original Montessori materials, but they were what I could get at the time I made them, and we have been using them successfully for five years now. :)