Today during family dinner my kiddo started finger-counting. I shared what I knew about a less popular system which allows counting to 12 on one hand:
Finger-counting systems in use in many regions of Asia allow for counting to 12 by using a single hand. The thumb acts as a pointer touching the three finger bones of each finger in turn, starting with the outermost bone of the little finger. One hand is used to count numbers up to 12. The other hand is used to display the number of completed base-12s. This continues until twelve dozen is reached, therefore 144 is counted. (Wikipedia)
Then, thanks to the wonders of Wikipedia, we all discovered something even cooler: base-10, arithmetics-ready system similar to abacus, for counting up to 9 on one hand and to 99 on two hands - Chisenbop.
Good visual intros are very important here, but are hard to find on Youtube. Here’s one which is great, and helped my little one to understand it well enough to represent some numers and do some counting with own hands.