Bernhard Riemann

Imagine you have a piece of paper, with a flat surface. You're going to draw a curve on it, like a squiggle. This is called a function. Now, pretend that you want to know everything about this function - how it behaves, where it goes, how fast it changes. Bernhard Riemann was a really smart man who figured out some special math tools to help us study functions like this in a really detailed way.

One of these tools is called the Riemann Sum. This is like dividing the curve into lots of tiny pieces (like a puzzle), and adding up the area of each piece to get a rough idea of the total area under the curve. But, Bernhard Riemann came up with an even better way to approximate the area, by using something called integrals. Basically, he figured out a special equation that can tell you the exact area under the curve.

Another important thing that Riemann worked on was called Riemann Hypothesis. This is a really tricky question that has to do with prime numbers (numbers that can't be divided evenly by anything except 1 and themselves). He wondered if there was a pattern to how these numbers were distributed, and came up with a whole bunch of rules and ideas that mathematicians still use today to study this problem.

Overall, Bernhard Riemann was an incredibly clever and innovative mathematician who helped us develop new techniques for understanding curves and solving really complicated problems.