You're reading: Posts Tagged: maths on the web

Take the 30 second arithmetic challenge

My wife’s grandmother is a fearsome character. She’s in her nineties but still has all her wits about her. In fact, she’s got more than her fair share of wits. Whenever we visit her, she hits me with a barrage of questions and puzzles collected from the last several decades of TV quiz shows and newspaper games pages. My worth as a grandson-in-law is directly proportional to how many answers I get right.

One of her favourite modes of attack is the “30 Second Challenge” from the Daily Mail. It looks like this:


You start with the number on the left, then follow the instructions reading right until you get to the answer at the end. It’s one of Grandma’s favourites because it’s very hard to do in your head when she’s just reading it out!

I decided it would be a fun Sunday morning mental excursion to make a random 30 second challenge generator

MacTutor History of Mathematics website creators honoured by LMS

Edmund Robertson & John O’Connor of the University of St. Andrews have been honoured by the London Mathematical Society for their pioneering MacTutor History of Mathematics website hosted at St. Andrews.

mactutor dudes

On 3rd July it was announced that both men have received the Hirst Prize, and Edmund Robertson has been been invited to give the associated Hirst Lectureship, all part of LMS 150th Anniversary celebrations.

Things I Made And Did

Since you’re here reading this, you probably know that on October 30th, Matt “Friend of the Site” Parker released his book, Things to Make and Do in the Fourth Dimension. If you’ve gone one further and read it, you might have seen the occasional reference to the website, If that website is the book’s DVD extras, this is the website’s extras. We’re going to peek behind the scenes and see how it all works. (Spoiler alert: the maths is powered by maths. It’s recursive maths, all the way down.)

Your favourite mathematical party trick has a snazzy website


Ariel Procaccia and Jonathan Goldman of Carnegie Mellon University have taken it upon themselves to make fair division problems easier to solve with a flashy new website called Spliddit (eyy, fuhgeddaboudit).

KaTeX is a (partial) alternative to (some of) MathJax

Khan Academy has released a new library to typeset mathematical notation on webpages, called KaTeX.

Have fun playing with curvature

Recently Tim Hutton and Adam Goucher have been playing around with hyperbolic tesselations. That has produced a {4,3,5} honeycomb grid for the reaction-diffusion simulator Ready, which Adam talked about on his blog a couple of days ago. Tim has also made a much simpler toy to play with in your browser: a visualisation of mirror tilings (the Wythoff construction) in spaces with different curvatures.

Hyperplay lets you select the kind of regular polygon you want to tile, and then your mouse controls the curvature of the space it sits in. Certain curvatures produce exact tilings of the space – for example, triangles tile a space with zero curvature – and you get projections of polyhedra for certain positive curvatures.