> However, spending time learning base 20 arithmetic has obvious disadvantages that the article ignores. They aren't learning base 20; they already use it in t

> However, spending time learning base 20 arithmetic has obvious disadvantages that the article ignores. They aren't learning base 20; they already use it in their language. They are learning how to write their language in their writing system. From the article: "The Alaskan Inuit language, known as Iñupiaq, uses an oral counting system built around the human body. Quantities are first described in groups of five, 10, and 15 and then in sets of 20." Not everyone counts in decimal. Base 20 exists in spoken French. For numbers 50-90, Danish uses base 20, in some cases mixed with fractions. There are other bases in other living languages as well.