Good grief, Murderous Maths is 12 years old and now all the books are being given new covers, an oil change and a new set of spark plugs. Who would have thought it eh? Definitely not me for a start.

I was first asked to write one book called "Murderous Maths" back in 1996. I honestly had no idea what I was supposed to do. After all Horrible History has lots of horrible things to write about, and so does Horrible Science, and Horrible Geography. But in maths you've got little sums like 2+3=5. Who gets murdered? Nobody.

But then I had two brainwaves. Brainwave one: I decided to make up some daft characters like aliens and barbarians and let them fight each other as much as they like. The good thing about this is that it gave me the chance to put a few jokes in, and I'd never seen a maths book with jokes before. Brainwave two: I realised that maths is the only subject in which you can do magic tricks! Therefore every MM book has got a few tricks in that you can play on your friends, or even just try for yourself to see how they work. Look, there's one coming now...

• Think of any number made of three different digits such as 268.
• Turn it round to get 862.
• Subtract the smaller number from the bigger one. Here we get 862 - 268.
• The digit in the middle of the answer will ALWAYS be a 9! Here the answer is 594.
• Now try it with your own three digit number! Oh go on, you know you want to.

So anyway, I got the first book written, but the only bit I hadn't done was the introduction. I wanted some explanation as to why the book was called "Murderous Maths" and so the very last thing I wrote was the first chapter featuring seven gangsters arguing over a restaurant bill. Philip Reeve ended up drawing Blade Boccelli and the boys to go on the cover, and to my amazement that picture now appears all over the world on the different translations of the book. Good for Blade!

When I wrote the first MM book I never imagined that 12 years later there would be 12 of them plus some MM puzzle books and the big colour Murderous Maths of Everything to come out next year! And when the first book came out, hardly anybody knew what the internet was, but now the www.murderousmaths.co.uk website gets about half a million visitors a year. I've made lots of virtual friends through the site and love answering their questions, so here's a few of the most common things I get asked:

Favourite MM Character?
Riverboat Lil.

Favourite Joke in the MM books?
When the gangsters trousers all fall down on page 13 of Desperate Measures

Favourite trick to perform on stage?
The Great Rhun of Jepatti's Square of Mystery in "MM Guaranteed to Mash Your Mind"

Favourite pathetic maths fact?
Halloween = Christmas! The reason why Oct 31 = Dec 25 is on page 127 of "Numbers The Key to the Universe"

Favourite foreign translation of the two words "Murderous Maths":
Let's have some big respect for the Italians who put this catchy title on the front of their books: "Ipotenuse, Incognite, Potenze, e Altri Misteriosi Misfatti Della Matematica." Wahey!

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