Approximation

For example, if you wanted to add 2.0002 and 2.0003, you can add 2 and 2, and it would be an approximation. If you are left with a balance of Dollar 78.23 you might want to say you are left with 80 dollars. In mathematics, this is written using the ${\displaystyle \approx }$ symbol (e.g., ${\displaystyle \pi \approx 3.1416}$).[1]
Archimedes used polygons to approximate a circle, and to calculate an approximation for ${\displaystyle \pi }$ as shown below: