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 a 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