# Blog

## Birthday paradox

By David Shaw, 3 September 2013

How likely is it that at least two people out of 30 will share a birthday?

## Blow bubbles!

By David Shaw, 27 August 2013

Keen to blow some seriously big bubbles? Try making this bubble mix!

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## Approximately pi facts about pi approximation day

By David Shaw, 22 July 2013

1. Pi (or π) is a number that helps describe circles. It links the width of a circle with its perimeter, or the radius of a circle with its area, or the width of a ball and its volume. It’s the same number no matter how big your circle is – about 3.14159265.

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## A giant step for twin primes

By David Shaw, 10 July 2013

Three and five. Five and seven. Eleven and thirteen. Prime numbers often appear as twins, only two apart. For hundreds of years, mathematicians have wondered – is there a biggest pair of twin primes, or does the list of twins keep going forever?

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## The Ancient Greek social network

By David Shaw, 9 July 2013

In the last decade, services such as Facebook have provided scientists with lots of information about current friendship links. However, they tell us little about historical friendships. So what might be the structure of an Ancient Greek social network?

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## Napier’s bones

By David Shaw, 18 June 2013

How did people multiply before calculators were invented? You could try doing it in your head, but you could also use a mechanical calculator, such as this set of Napier’s bones.

## Arrow maze

By David Shaw, 21 May 2013

Here’s a fun puzzle! It’s a maze with no walls. So what’s keeping you on track? Well, this maze is made of arrows – it’s an arrow maze!

## Anamorphic art

By David Shaw, 23 April 2013

Check out this trick! By colouring in boxes, you can make a strange blobby picture that transforms when reflected in a curvy mirror!

## Imperial pie

By David Shaw, 14 March 2013

The measurements in this recipe are in non-metric units. You will need to change them into metric before you can make the recipe!

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