# January, 2013

## Book review: Alex’s Adventures In Numberland by Alex Bellos

When I gave a talk about the Curious Maths Of Alice In Wonderland recently, I was extremely proud of myself for coming up with the slide title 'Here's Looking At Euclid'. I even flagged it up as the best joke in the talk. You can imagine my horror to discover

## Dividing by 9 – Secrets of the Mathematical Ninja

Dividing by 9 has always been an awkward one for the mathematical ninja - it ought to be a simple operation, but for some reason it's never stuck. However, there IS an easy way that involves not much more than adding up and (possibly) using your fingers to track a

## Silly Questions Amnesty

It's not only Burns' Night, but it's also Impala The Koala's birthday! You can celebrate either or both of these by asking a question in the comments - I'll answer as nicely as I can!

## James Bloody Grime and his blasted logarithms

It's typical of James Grime to ask a really interesting question just as I'm going to bed. I was going to sleep like a log, but suddenly I was awake liking logarithms. I've been asked, for what base a does the equation $\log_a(x) = a^x$ have only one solution. If

## The Rule of 72: Secrets of the Mathematical Ninja

Despite what you may have heard, Einstein probably never said that compound interest was the greatest force in the universe. It is, however, an interesting beastie. The Mathematical Ninja likes quick fixes. The Mathematical Ninja LOVES estimating powers of e, but he loves quick-and-dirty estimates even more. Especially to one

## Silly Questions Amnesty

Go on, give me a question. You know you want to!

## How to think about co-ordinate geometry (Part III: Circles, tangents and so on)

This is the third and final part of the how to think about co-ordinate geometry series. Due to a failure of calendar-reading, I appreciate this is going out a few days after the C1 and C2 exams, but hey-ho. If you're relying on this blog for your revision tips, you

## Lives of the Mathematical Ninja: Blaise Pascal

My current hero of mathematics - like Ramanujan - died before he was 40. Like Ramanujan, he'd already revolutionised maths by that point. Blaise Pascal (born in Clermont-Ferrand in central France in 1623) can reasonably claim to have invented probability theory, and the first calculator; he was also the first

## Silly Questions Amnesty

Another Friday? Already? It's as if they come around more or less weekly. What questions do you have this week? Leave them in the comments and I'll answer if I can!

## How to think about co-ordinate geometry (Part II: curves, tangents and normals)

This is part two of a three-part series about co-ordinate geometry. In part I last week, I went into tedious detail about the equation of a line. This week, I’m going to take it a bit further and go into curves. Next week, you get to see circles. So, what