# Try and guess this mystery number!

### By Dallan Hunt

This number helps us understand how the patterns of stripes form on zebras; it helps us design and implement satellite communication around the world; it even allows us to safely land a rover on Mars to advance science in revolutionary ways; if that wasn’t enough, it also helps us understand how the entire universe expands. Surprisingly, this number was conceived by ancient Babylonians thousands of years ago before modern calculators or computers even existed. If you haven’t guessed it yet, the mystery number is pi, or π. This number is so important that there is an annual holiday celebrated around the world, called **Pi Day – March 14th.**

## What is the number Pi?

As important as the number pi is, it might shock you to find that no one knows exactly what it is.

Wait, what?

It’s true.

Pi is a special number that you might recognize to look like this: 3.14…But what’s so special about it is that the digits never end and never repeat in a pattern. This is what mathematicians call an irrational number. For these reasons, we don’t know all the digits of pi, and never will.

When biologists, engineers, and cosmologists make calculations using pi, instead they use an approximation – which is a decimal close to pi. Often in school, students will use 3.14; NASA, on the other hand, uses 3.141592653589793. Based on how accurate you need to be, you can choose fewer or more digits as you like.

Most people recognize pi from how it relates to circles.

If you take the distance around a circle (called circumference (C)) and divide it by the diameter (the distance across the circle through the middle (d)), you get pi – every time, and for every circle, no matter how big or small. It is this universal property of pi and its relation to geometry that embeds it in nearly every branch of science.

A Tasty Activity

If you are interested in introducing students to the important properties of circles, here is a great activity. Students can learn about diameter, circumference, and yes…pi. All you need is a round snack, (an orange or cookie will do), a piece of string, and scissors.

This activity provides a great hands-on demonstration of the properties of circles learned in geometry. Geometry is one of the major parts of math curriculum and is found in early grades, right up through high school and beyond.

If you are looking to help your child improve in geometry, along with all the other areas of math, take time to make the right choice. Sylvan’s extensive math program covers all the important areas, through our personalized learning approach. We can help your child build important foundation skills and also work ahead on enrichment. Our program includes:

- Numbers and operations
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- Algebra
- Data Analysis, Statistics, and Probability

If you're interested in giving your child the learning experience of a lifetime, reach out to your local Sylvan Learning. A knowledgeable Center Director will answer any questions you have, and help you take the next step.

**Sources**

- https://www.biophysics.org/blog/pi-is-encoded-in-the-patterns-of-life
- https://www.honeywell.com/us/en/news/2020/03/5-ways-our-engineers-use-pi
- https://www.jpl.nasa.gov/edu/learn/list/oh-the-places-we-go-18-ways-nasa-uses-pi/
- https://www.jpl.nasa.gov/edu/news/2016/3/16/how-many-decimals-of-pi-do-we-really-need/