The idea arose out of a puzzle involving 2 circles and a square that Nathan shared on a hike to Vermeilley December 2025, details are in the blog but also replicated here. Given 2 touching circles of radius, r, find the area of the square EFGH.
Then Peter Taylor shared a set of Christmas puzzles that were great fun.
https://www.sciencealert.com/mathematician-shares-10-festive-brain-teasers-that-anyone-can-try
and here are the solutions although we don’t agree with all of them
https://www.sciencealert.com/mathematician-shares-solutions-for-10-festive-brain-teasers?utm_source=news.sciencealert.com&utm_medium=newsletter&utm_campaign=today-s-top-science-news
After many emails between Nathan, Peter T and Mark 2Ts the puzzles were solved but we thought it would be a good idea to share and solve other problems, hence this puzzlers group.
Not a puzzle but certainly interesting was the fact Ross shared on the Creux du Van hike last June
Essentially take any 4 digit number and rearrange the digits highest to lowest and lowest to highest. Subtract one of these from the other to give a new 4 digit number and repeat the procedure. This ultimately produces 6174.
On an earlier walk, Mike Price also introduced a puzzle from the Guardian involving a circle. How to drop a perpendicular from any point onto a diameter without using any measuring device. No compasses, no marked ruler, just a pencil and an unmarked straight edge. This was posed by a Russian prime minister, Mikhail Mishustin, on a visit to a school.
https://www.theguardian.com/science/2021/sep/20/can-you-solve-it-russias-prime-minister-sets-a-geometry-puzzle?CMP=share_btn_url
Above seems to indicate there will be some interest in a puzzlers group. Also an initial note immediately returned the names of 10 members who are interested.