A prime number is a natural number greater than 1 that cannot be formed by multiplying two smaller natural numbers. The prime numbers less than 100 are: 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, and 97. Counting these gives a total of 24 prime numbers.