Every day here at *Plus* is a celebration of maths! And one of our favourite ways to share the joy is to distil some of our favourite ideas from the mathematical sciences into just a few words. Our *Maths in a minute* library explains key concepts in brief introductions for when you want facts and you want them fast.

So to celebrate the beauty of maths today on pi day (14th March, or 3.14 if you write things the American way with the month coming first), here are just a few of our favourite maths in a minute!

We've published over 150 so far and we're always adding more - you can find them all here!

### Find out some fundamental maths in a minute!

Triangles — Ah the humble triangle. This simple shape is one of the first we ever come across. But perhaps you didn't realise just how important triangles are...

Mathematical models — A mathematical model is a description of a process in the world around us that is written in terms of mathematical expressions. Find out more in this basic introduction to one of the most powerful tools in science and engineering.

Exponential growth — What do we mean when we say that something grows exponentially? Find out in this very easy introduction, suitable for anyone curious to know more!

### Take your maths further in few minutes!

Calculus — Curious about calculus? This accessible introduction brings all the ideas together in one place so it's an easy intorduction for those meeting calculus for the first time!

Groups — Groups are a more abstract idea in maths, but this slightly longer introduction gives you an easy way in by thinking about clocks and symmetry.

Topology — When you let go of the notions of distance, area, and angles, all you are left with is holes.

### Discover some statistics and data science in a minute!

Probability distributions — Probability distributions help us describe processes with uncertain outcomes. They are incredibly useful, but what exactly are they?

Algorithms — The word "algorithm" has probably got more usage over the last few years than it has in its entire history. But what exactly is an algorithm?

Machine learning and neural networks — We are surrounded by examples of applications of machine learning every day, such as the speech recognition in our phones. But what is it and how does it work?

### Fascinating physics in a minute!

Thermodynamics — Tea gone cold? Don't worry, you can cheer yourself up with the theory of thermodynamics.

Einstein's general theory of relativity — What would happen if the Sun suddenly exploded? Einstein wondered the same thing, and completely changed our understanding of the Universe.

The double slit experiment — This simple introduction to one of the most famous, and most strange, experiments in physics, is one of the most popular articles on *Plus*!

### And unexpected maths fun a minute!

The Fibonacci sequence — The origin story of this famous sequence stars some cute, fluffy bunnies.

The Sydney Opera House — Discover the mathematical puzzle behind this iconic structure.

Penguins — We celebrated penguin awareness day (20th January) with a look at some penguin maths.

*Some of this content was produced as part of our collaboration with the Isaac Newton Institute for Mathematical Sciences (INI) – you can find all the content from our collaboration here.
The INI is an international research centre and our neighbour here on the University of Cambridge's maths campus. It attracts leading mathematical scientists from all over the world, and is open to all. Visit www.newton.ac.uk to find out more. *