- Simon Ellis

# New Maths? - an update...

**There has been quite a lot of feedback, some quite vitriolic (mostly on Twitter), about the "discovery" referred to in the previous blog post so I thought I would clarify a few things:**

**No - it's not strictly "New" Maths but...**

**It was discovered independently by an 11 year-old boy who was very excited to share his discovery so it was NEW to him.****None of the teachers at his school - nor anyone they consulted - had seen it before so it was NEW to all of them, too.****I had only seen something like it as an exercise in Modular Arithmetic (and not as a divisibility test) so when I was asked to come up with a watertight proof that 11 year olds could understand (see below) that was NEW to me, too.**

**At the time, I did an extensive internet search and could only find one small reference tucked away inside a Wikipedia page - without the proof in my original blog...**

**...and, finally, I never actually said it was "NEW" Maths. There was always a question mark in the title (and in the first line of the article) and I am very grateful to those who have answered that question by pointing out other places where they have seen this divisibility test before - especially those who did it with good grace!**

**Let us all celebrate creativity in Mathematics and be grateful that there are 11 year olds out there who do this sort of thing for fun!**

**Simon Ellis**

**20th November 2019**