Leonhard Euler

Hello! My name is Leonhard Euler. I was born in a beautiful country called Switzerland on April 15th, 1707. My father was a pastor, and he loved numbers almost as much as I did! He taught me how to solve puzzles with math, and I thought they were the most exciting things in the world. I loved learning so much that in 1720, when I was only 13 years old, I went to a big school called a university to learn even more about numbers and how they work.

When I grew up, I moved to a city called St. Petersburg in Russia in 1727 to work as a scientist. While I was there, I heard about a famous puzzle from a city named Königsberg. The city had seven bridges connecting different parts of the land, and everyone wondered if you could take a walk and cross every single bridge just one time without going over any bridge twice. People had tried for years to figure it out! In 1736, I finally solved it. I realized you didn't need to walk it; you could draw it! I used dots for the land and lines for the bridges and proved that it was impossible to do. My fun solution started a whole new kind of math called graph theory, which is still used today to solve all sorts of problems.

I always wanted to make math easier for everyone to understand, so I came up with new symbols that we still use. If you've ever seen 'f(x)' in a math problem, that was my idea! It helps people write about math ideas more simply. As I got older, my eyesight started to fade, and it became very hard for me to see. But that didn't stop me from doing what I loved! I had a super-powered memory and could picture all the numbers and equations perfectly in my mind. I kept working and discovering new things with the help of my family, who would write down all the ideas I told them.

I lived a long and happy life filled with numbers and puzzles. I lived to be 76 years old. Today, people remember me as one of the most brilliant mathematicians who ever lived. The symbols I created and the problems I solved are still used in classrooms all around the world. I hope my story shows you that curiosity can lead to amazing discoveries and that even when you face a challenge, you can find a new way to see the world.