Do you have a favourite equation? Peter Alfeld of The University of Utah has **a collection** he thinks are important or intriguing. My personal favourite, Euler’s identity, is his first on the list.

e^{i}^{π}= -1

For more on beautiful equations try the **17 equations that changed the world on the World Economic Forum** where for each equation we have the following information:

- What does it mean?
- History
- Importance
- Modern use

Or from BBC Earth, have a look at **“What is the most beautiful equation?**”

For UK school age students note the **famous equation poster contest** from the excellent Maths Careers site. This competition closes on Friday 8th June; winners in each age group will win an Android tablet. There will also be five ‘highly commended’ certificates awarded in each group.