> this goes so quickly Many people don't realize how fast it is to work on abacus (or soroban in Japanese). Here is an example of what a 7 year old can do htt

> this goes so quickly Many people don't realize how fast it is to work on abacus (or soroban in Japanese). Here is an example of what a 7 year old can do https://www.youtube.com/watch?v=GQtqlB-jXO0 https://www.youtube.com/watch?v=GQtqlB-jXO0 For many years I always did my taxes and other accounting using an abacus because it was sooo much easier than longhand (this was before calculators). There is the famous Feynman story as well: https://www.ee.ryerson.ca/~elf/abacus/feynman.html https://www.ee.ryerson.ca/~elf/abacus/feynman.html But you wouldn't impress an ancient Greek very much by taking cube roots quickly because there wouldn't be much call for that.