# Lesson 3: Circle. Volume of a Cylinder. Scientific Notation

In this lesson you will learn about scientific notation and its significance when working with very large and very small numbers.

Scientific notation is widely used in Physics, Astronomy and Chemistry. For example, it could be used to express the volume of water in a large lake. Instead of writing all the zeros we multiply the number by a certain power of 10.

You will also learn how to calculate area and circumference of a circle.

You will discover the importance of the Pi number.

Here are the first 100,000 digits of Pi

The lesson teaches you how to determine the volume of a cylinder (a 3D shape with circular bases and a rectangular lateral part). You will also learn what calculating the volume means and what units should be used.