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### How Ultimate is Ultimate π day?

This year, π day will be celebrated, as always, on 14th March. Unlike most years, π day will be more accurate than usual – owing to the fact that the year, 2015, will give the date 3/14/15 (provided you’re using a US calendar date format) – and for this reason, some people are calling it Ultimate π day. But how truly Ultimate is it?

### How I Wish I Could Celebrate Pi

People with an interest in date coincidences are probably already getting themselves slightly over-excited about the fact that this month will include what can only be described as Ultimate π Day. That is, on 14th March 2015, written under certain circumstances by some people as 3/14/15, we’ll be celebrating the closest that the date can conceivably get to the exact value of π (in that format).

Of course, sensible people would take this as an excuse to have a party, so here’s my top $\tau$ recommendations for having a π party on π day.

### From the Mailbag: Golfing Combinatorics

Sam’s dad is in a mathematical conundrum – so she’s asked Katie, one of our editors, if maths can save the day.

Dear The Aperiodical,

My dad is going away on a golfing holiday with seven of his friends and, since I know a little bit about mathematics, he’s asked me to help him work out the best way to arrange the teams for the week. I’ve tried to work out a solution, but can’t seem to find one that fits.

They’ll be playing 5 games during the week, on 5 different days, and they’d like to split the group of 8 people into two teams of four each day. The problem is, they’d each like to play with each of their friends roughly the same amount – so each golfer should be on the same team as each other golfer at least twice, but no more than three times.

Can you help me figure it out?

Sam Coates, Manchester

### Twitter’s favourite fictional mathematicians

In an idle moment of wondering, I asked a simple question on Twitter:

The response was overwhelming. Here’s a guide to the non-existent number crunchers you should know about, and some you probably already do.

### ‘All that glitters is not golden’: a Fibonacci Day Roundup

Yesterday was 23/11, also known in some parts as 11/23, and you may recognise this as being a date made of the first four Fibonacci numbers. (Such numerical date-based Fibonacci coincidences haven’t been as exciting since 5/8/13, but at least this is one we can celebrate annually.) This meant that mathematicians everywhere got excited about #FibonacciDay, and spent the day talking about the amazing sequence. Here’s a round-up of some of the best bits, so you can celebrate Fibonacci day in style.

### The Hidden Maths of Eurovision

Every year, the Eurovision Song Contest brings with it fresh accusations that the results are affected more by politics than music. But how much of the outcome is in fact determined by mathematics?

### Matt Parker talks percentages

If anyone caught BBC1’s consumer moanfest Watchdog this week, they may have been pleasantly surprised to see Aperiodicobber Matt Parker featured in the show. Following a segment about a UK sports chain and its shocking use of the classic ‘UP TO 70% OFF’ ruse, they invited Matt on the show to explain how to calculate percentages more easily, and so that Anne Robinson could mock him for being Australian, apparently.

Since the tips Matt presented were useful, we at the Aperiodical thought it was worth reproducing Parker’s Patented Percentage Ploys here, for your reference.