The Monkey Buddha Archives:
I recently came across an article on Ancient Origins about the re-introduction of Mayan numbers & math concepts to the indigenous children of Mexico, with positive results.
It takes a little bit of effort for someone (like me) who grew up learning the Western numerals and decimal Base 10 system to wrap their head around the use of bar & dot symbols in a Base 20 configuration.
It appears that the use of bars & dot symbols in the Mayan number system may have originate with the physical representations of sticks and rocks, as seen in this video linked in the article. The use of the labeled grid really helped me visualize the Base 20 system.
The article also has a link to the online game below, that teaches the fundamentals of Mayan numbers & mathematics. I've played it and found that I was able to get better at using the symbols & vigesimal counting system.
This chart shows the number symbols & the placement grid below: