What is a good way to memorize the prime numbers 1-100?

Question

and please dont say study!

i know that!!!!

i just want an easier way that i can memorize the prime numbers...

maybe like a song or something... or a poem, something i can memorize..... its just harder to memorize the numbers by them selves.. THANKS!

Answer 1

Why would you need to memorise them?

It's pretty easy to just figure out if a number is prime on the fly, can you divide it by anything other than itself and one?  Then it's not prime, are you trying to memorise for a test or something along those lines?

It seems like a weird question, but I'll try to give you some tips;

All the primes from ten to one hundred end in one, seven, nine or three.  Straight away you can discount any number ending in 2,4,5,6,8 or 0.    Obviously because all numbers ending in 0 are divisible by ten so not prime, same with numbers ending in 5 being divisible by 5 etc.

If you remember "two, three, five, seven" (the first four primes), then "one seven nine and three" (what the remaining primes have to end with) you can quickly count or discount most the numbers, then just try to divide it by something other than itself or one.