Me Too has mastered the 100 chain! He can count very well by 10's both forwards and backwards.
Kal-El worked on the squaring chain of seven...
...and also the cubing chain of seven.
Ack! Rather than stock the chains cabinet fully from the beginning, I elected to fill the cabinet gradually as Kal-El adds each chain. Consequently it was only last month, three years after purchasing our chains and cabinet, that I discovered that we were missing the seven white 7x7 bead squares (we have double the amount of yellow 4x4 squares instead). The only place I could find that sold the squares separately was Nienhuis. I ordered six of them (one came with the short bead chains). Four arrived this week (several weeks after I ordered them) and two are on backorder. Does that company actually stock anything?