What are prime numbers and why do they matter?
Stubborn Number Loners
What are prime numbers and why do they matter?
Here's a question that has hypnotized mathematicians for thousands of years: which numbers refuse to be split into equal groups? Some numbers are friendly and cooperative. Others are stubborn loners. Those loners have a name — prime numbers — and they turn out to be the secret backbone of almost everything in math.
Let's start with the cooperative ones. Take the number 12. You can split 12 into 2 rows of 6, or 3 rows of 4, or 4 rows of 3. It folds up neatly in lots of ways. Numbers like this are called composite — they're built out of smaller pieces stacked together.
