46th Carnival of Mathematics

The 46th Carnival of Mathematics is now online, hosted by Walking Randomly. I was happy to see one my blog posts listed there. Cool! These carnivals are great. I’ll have to look into how to host one in the future. I don’t know who runs them. Advertisements

A 10-adic number that is a zero divisor

A few weeks ago I wrote about p-adic numbers. I mentioned that if p is not prime, then the p-adic numbers can have zero divisors; that is, there are nonzero numbers and such that . Today Foxmaths! wrote about a 10-adic number (although not using that terminology) such that (in other words is an idempotent…