## You're reading: Posts Tagged: MathsJam

### Zeckendorf cup arithmetic

My 5-minute talk at the big MathsJam conference this weekend was about some stacking cups that my daughter is too young to appreciate. Here’s the really quick version, in just over a minute:

I gave the answer at MathsJam, but the title of this post contains a big hint that should get you there with a bit of googling.

### Baking Babylonian cuneiform tablets in gingerbread

The MathsJam conference has a baking competition. My friend the archaeologist Stephen O’Brien tweeted a while ago a link to a fun blog post ‘Edible Archaeology: Gingerbread Cuneiform Tablets‘. Babylonian tablets are among the earliest written evidence of mathematics that we have, and were produced by pressing a stylus into wet clay.

So it was that I realised I could enter some Babylonian-style tablets made from gingerbread.

I made a gingerbread reconstruction of a particular tablet, YBC 7289, which Bill Casselman calls “one of the very oldest mathematical diagrams extant“. Bill writes about the notation on the tablet and explains how it shows an approximation for the square root of two. I’m sure I didn’t copy the notation well, because I am just copying marks rather than understanding what I’m writing. I also tried to copy the lines and damage to the tablet. Anyway, here is my effort:

In addition, I used the rest of the dough to make some cuneiform biscuits. I tried to copy characters from Plimpton 322, a Babylonian tablet thought to contain a list of Pythagorean triples. Again, Bill Casselman has some interesting information on Plimpton 322.

Below, I try to give a description of my method.

### Maths at the British Science Festival 2018

Guest author Kevin Houston has written a round-up of maths-related events at next week’s British Science Festival.

The British Science Festival is taking place in Hull and the Humber 11-14th September. There are lots of talks so I’ve put together a handy guide to talks with a mathematics-related theme.

### MathsJam Gathering: A Review

It was with trepidation that I booked tickets for the MathsJam Gathering in 2015. I loved the sound of the event, but what if everyone else was cleverer than me? What if people thought I was a fraud because I wasn’t an academic? What if nobody talked to me? I needn’t have worried. MathsJam is one of the friendliest, most welcoming events I’ve ever experienced. Lots of people talked to me, I learned new things, I laughed a lot. I’ve since been to two more gatherings, and have already booked for the next one in November.

### Exactly how bad is the 13 times table?

Let’s recite the $13$ times table. Pay attention to the first digit of each number:

\begin{array}{l} \color{blue}13, \\ \color{blue}26, \\ \color{blue}39, \\ \color{blue}52 \end{array}

What happened to $\color{blue}4$‽

A while ago I was working through the $13$ times table for some boring reason, and I was in the kind of mood to find it really quite vexing that the first digits don’t go $1,2,3,4$. Furthermore, $400 \div 13 \approx 31$, so it takes a long time before you see a 4 at all, and that seemed really unfair.

### Approaching Fermi problems with the approximate geometric mean

I gave a talk on Fermi problems and a method for approaching them using the approximate geometric mean at the Maths Jam gathering in 2017. This post is a write up of that talk with some extras added in from useful discussion afterwards.

Enrico Fermi apparently had a knack for making rough estimates with very little data. Fermi problems are problems which ask for estimations for which very little data is available. Some standard Fermi problems:

• How many piano tuners are there in New York City?
• How many hairs are there on a bear?
• How many miles does a person walk in a lifetime?
• How many people in the world are talking on their mobile phones right now?

Hopefully you get the idea. These are problems for which little data is available, but for which intelligent guesses can be made. I have used problems of this type with students as an exercise in estimation and making assumptions. Inspired by a tweet from Alison Kiddle, I have set these up as a comparison of which is bigger from two unknowable things. Are there more cats in Sheffield or train carriages passing through Sheffield station every day? That sort of thing.

### Review: Closing the Gap, by Vicky Neale

Did you read Cédric Villani’s Birth of a Theorem? Did you have the same reaction as me, that all of the mentions of the technical details were incredibly impressive, doubtless meaningful to those in the know, but ultimately unenlightening?

Writing about maths, especially deep technical maths, so that a reader can follow along with it is hard – the Venn diagram of the set of people who can write clearly and the set of people who understand the maths, two relatively small sets, has a yet smaller intersection.