This is a simple estimation for how many prime numbers lie between point A and point B. It's not accurate from 1-10 because the more primes already found, the more accurate the readings. Since this zone is just establishing the primes, it has a tendency to underestimate. This works by the principal that as the numbers multiply, they will grow in an distance exponentially for that multiple. This means that we just need to layer it. I found that by using factorials, you can cancel out repetitions easier. This finds roughly the percentage of numbers that will be prime. By multiplying this by the range from A to B, you can calculate about how many primes are between two points.
Sorry for the explanation. It's kind of hard to explain. :D ADVERTIZING IS ALLOWED!!! I love to see your projects! If you have any that you would like to share with me, please do. :D