I haven't seen a useful diy post on this. Most involve buying bits of wood of different weights. It sounded so hard, I gave up instantly! I mean, I did ask the shop if I could have their sample floor boards, but that was it.
I don't know what happened then. I must have been reading a book on the method. I suddenly had an idea. Did the tablets have to be made from wood? Did they have to be a specific size? No and no. The only requirements I could find is that they are all the same size and different in weights.
So, matchboxes with marbles will do! And this is really easy. I found that the tablets weight 25 to 35 grams. Which happens to correspond exactly to a matchbomatchbox with 4 to 6 marbles! A marble is generally 5g, and so wad my matchbox.
This is what you need
6 empty match boxes, the small ones
wrapping paper of 2 colours
some cotton or stuffing to stop marbles from moving (mine didn't need this as the marbles were slightly big. )
You fill 2 boxes each with 4, 5, or 6 marbles and mark them clearly. Now you have 3 pairs of different weight. Feel them! It's not an easy exercise.
Take one box of each weight and wrap them in paper 1. Mark the boxes on the bottom as you go. Then wrap the other 3 with paper 2. Don't forget to mark them!
That's it. Easy as pie. I marked them with only a tiny mark, but I now think a mark Seb can use would be better. This is the control and the child can check if he's correct.
Like I said, it's hard and it helps if you move the weight up and down in your hand. But once you got it, it's easy. And it would be even easier to a child. According to Weber-Fechner law, you can discern a 5% weight increase in an object. So, you should be able to tell the difference between 20g and 20.1g! A 25% weight increase is a lot! But it takes a bit of practise and focus and closing your eyes and sticking your tongue out.
I realy enjoy working with this material!