this is to help them be identified and to keep track of them with the referee's association
6 in USA and 3 in UK
If it can not be divided by anything as a whole..new answer...The above is true, but "primeness" testing has become a major research branch of theoretical math. If I give you a large number, (eg:...
A prime number cannot have any number multiplied to make that number, except for one. example: 9 is not prime because 3 times 3 is 9.
One way you can easily find out is trying to find a pattern. If it is counting by 5,10,or 15. Another way is you could guess, then check your answers.