How many prime numbers are there between 1 and 100?

Question

In addition, is there any shortcut method to remember how many prime numbers there are between a range such as 1 to 50, 30 and 80 etc.?

Accepted Answer

To make it easy to remember, we can create the following table. Range Prime Numbers Count 1 to 10 2, 3, 5, 7 4 11 to 20 11, 13, 17, 19 4 21 to 30 23, 29 2 31 to 40 31, 37 2 41 to 50 41, 43, 47 3 51 to 60 53, 59 2 61 to 70 61, 67 2 71 to 80 71, 73, 79