# May, 2014

## Why are outliers defined like THAT?!

My own imagination asks: Why is an outlier defined as 1.5 interquartile ranges outside of each quartile? Great question, imagination! The simple answer, I think, is that it's a nice and easy thing to work out, and 1.5 interquartile ranges is quite a long way from the central box (if

## Boodles: Secrets of the Mathematical Ninja

"You can use BIDMAS," said the student, and the Mathematical Ninja gave him a piece of paper and a marker. "Write BIDMAS on here, really big." While the student complied, the Mathematical Ninja fired up the flamethrower. "Hold it up in front of your face." "You know, I'd really rather

## Nine ways to revise for the GCSE Calculator paper

A student asks: Hi, I am struggling with trying to revise for my GCSE maths calculator mock… I was wondering if you could give a few tips on how to revise for this exam in particular. There's a commonly-held belief that the calculator paper is easier than the non-calc one,

## Recurring decimals: Secrets of the Mathematical Ninja

"May I borrow some paper?" asked the student, meekly. He knew he should have come prepared; he feared for his safety, as the Mathematical Ninja's reputation preceded him. "BORROW?!" hairdryered the Mathematical Ninja. "BORROW?! Why on earth would I want the paper back after you've defiled it with your profane...

## The C1 Last-Minute Panic Checklist

OK, OK, stop screaming! I KNOW C1 is only a few days away, I know you're underprepared, but panicking isn't going to help anything. It's a pretty common - and heartbreaking - thing for tutors and teachers to see: a student who's waltzed through GCSE getting to the end of

## A student asks: why do you love maths so much?

A question I don't remember ever having been asked before: Why do you love maths so much? It's a really hard question to answer - if you asked someone why they like music or football, they'd probably shrug and say 'I just do!' There are loads of things I love

## Carnival of Mathematics, 110

It's the 110th Carnival of Mathematics - and I fear I've drawn the short straw. I suppose, as the numbers climb higher, there are fewer interesting facts to go around. However, a few that jump out: it gives the minimal value (-5) of the Merten's function ( http://en.wikipedia.org/wiki/Mertens_function ) it's

## Finding constants for a line or curve – Secrets of the Mathematical Ninja

The Mathematical Ninja stopped dead in his tracks. Not literally, of course: immortal beings don't die. He turned his head slowly towards the student, unsure what was going on. He probably had in mind his recent OFSTED report, which had -- while praising the results of the students that survived

## Wrong, But Useful: Episode 14

In the (very) late April episode of Wrong But Useful, with @reflectivemaths and @icecolbeveridge: Colin has laser eye surgery and doesn't care about Dave's health... ... but does care about 20481 . Colin mistakenly credits @notonlyahatrack for getting to 2048, when he meant 4096. Links: Numberphile, Cav, artificial intelligence 1