# April, 2013

## Co-ordinate geometry revision quiz

This quiz is to get you up to speed with straight lines, gradients, distances and midpoints. Enjoy!

## Basic Maths Skills: Listening to the budget (big numbers)

I caught a bit of the Chancellor's budget speech recently. I try to avoid doing silly things like that, it just makes me angry. However, I was interested to find I was hearing big numbers bandied about without really knowing what was big in the context of a national budget.

## Silly Questions Amnesty

That'll be the last SQA in April, that will. Doesn't time fly when you're having fun?

## Why is the volume of a pyramid what it is?

My podcast co-host Dave Gale asked an interesting question: why is the volume of a pyramid $V=\frac{1}{3}x^2h$? Dave being Dave, he doesn't want to mess around with 3D geometry, so I figured I should find an explanation a smart GCSE student would be able to grasp. I'm going to start

## The Mathematical Ninja’s Ten Coolest Numbers

The Mathematical Ninja took one look at the list of the 10 coolest numbers and scoffed. "Those," he said, "are not the ten coolest numbers." "What are, then?" said the student. "Remember, nothing for cultural significance, so you can't have 42. And no physical constants, so $g$ is out." "I

## Silly Questions Amnesty

Roll up, roll up! Well, that's my lunch ready. Now, how about some silly questions for pudding?

## A reader asks: how long would you last in a casino?

Imagine you go to the casino with \$100 in one-dollar chips and decide to play the roulette wheel. You've nothing better to do; you can stay there as long as you have chips left. How long can you expect to carry on playing? Let's pick on the 50-50 bets (such

## Co-ordinate battleships

A slight change of pace this week: a game rather than a quiz. Can you sink the enemy ships by firing at the right co-ordinates? (If the grid doesn't show up, try refreshing.)         Your guess:

## QTS Skills: Working out a percentage of a number

My colleague Adrian has submitted a guest post in the form of a video explaining how to answer a typical QTS mental arithmetic question on percentages. Adrian? Take it away. Or rather, divide it and multiply it!