# What should you get a mathematician for Christmas?

Behind today’s door… The Chalkdust guide to Christmas presents

This post was part of the Chalkdust 2016 Advent Calendar.

Welcome to the seventh day of the 2016 Chalkdust Advent Calendar. Today we bring you a concise list of maths-related gift ideas, made to entertain the mathematician within you, and disappoint your not-so-mathsy family and friends. Let’s begin!

## Things nobody wants for Christmas

A classic, the Casio FX. A great present for anyone who is doing GCSE maths or equivalent. A terrible one otherwise. Most of the general public seems to be under the impression that all mathematicians do is solve large sums whilst punching away on their calculator. We’d be happy to remind them that this is the job of an accountant. “No, I do not want to calculate how much each person is paying when we split the bill. No.”

Scented candles. Uncreative, almost as festive as Febreze Fresh Cut Pine. Would avoid in all cases unless incredibly desperate and in dire need of a Secret Santa present.

## Things some people want for Christmas

### Fibonacci Clock

Why? Because its almost as hard to read as this animal clock.

The clock is made up of 5 squares, each with side lengths representing the first 5 terms of the Fibonacci sequence (1,1,2,3,5) arranged in a spiral form. Red indicates the hour, green, the minutes and blue is for when both hour and minute are the same.

To tell the time, simple add up the green and blue squares and multiply by 5 for the minutes (be aware this clock is only accurate to 5 minutes) and the hour is sum of the red and blue squares.

A terrible clock to have in an exam, a great one otherwise.

“So what’s the time?”
“2×2 white 3×3 white 1×1 green 1×1 red and 5×5 blue.”
“What?”
“It’s 6:30.”

### Games

A safe, usually successful and usually amazing choice for cold winter days. Here are my picks for games to play between $n$ or fewer person(s).

### Antivirus

Rush Hour’s less appreciated second cousin twice removed. It comes with a booklet of starting positions with difficulty ranging from really easy to really not easy. Simple looking, though terribly addicting.

### Hive

A personal favourite boardless strategy game made for 2 players. The objective is to completely surround the ‘Queen Bee’ with pieces of any colour (white or black). Pill Bugs prove to be great for strategic game play, and Spiders not so much. Grasshoppers are just as under appreciated as Spiders.

### SET Mini round

The same sets, just tinnier.

Because regular SET is so 1974.

### Symmetry Groups Wrapping Paper

To top it off, some lovely Symmetry Groups wrapping paper, of which there are 17 different designs, enough for you, your friends and extended family.

Image credits: CC-BY-SA: Calculator, Jörg Reddmann. Candle, smittenkittenorig.

TD is an undergraduate at UCL who actually understands the 1967 James Bond spoof Casino Royale, starring David Niven, Peter Sellers, Woody Allen, and Orson Welles as Le Chiffre.
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