This thing was made with Tinkercad. Edit it online https://www.tinkercad.com/things/2wm3O4XAkTZ

I designed this to help with my grand daughter's homework. there is a hole in the centre of each for a wire or pin to be inserted so that they can be mounted onto a backboard of cork, felt, polystyrene etc. I used tinkercad and it took about 10min to design but I thought it could be of use, enjoy.