How do we know that there are an infinite number of prime numbers?
A prime number is any number that can be divided only by itself and one. For example, 7 and 11 are prime numbers, but 12 is non-prime (because it can be divided by 2, 3, 4 and 6 in addition to itself and one). Around 300 BCE, Euclid deduced that there must be an infinite [more...]


















