@vega So glad you’ve enjoyed Elemental. I'm still working my way through them. 😀 Now I'll recommend a book: Numbers and the Making of Us: Counting and the Course of Human Cultures - www.amazon.com/gp/produc... . I read it a couple of years back. He includes info about cultures who don’t do counting at all, and about how the human brain is wired to count to 3 but not beyond.