We all know that prime factoring is to factorize a number to multiplications of primes, for example, \(4=2 \times 2\). (Note: arrange the primes from small to big.) Remove the multiple signs, you'll get a number: 22. Repeat the steps, \(22= 2 \times 11\). Remove the multiple signs to get 211, which is a prime. Now, lets do this for 6, which you can find a prime in just one step: \(6=2 \times 3\), get 23, a prime. 8 is a bit tricky, you'll need to do a number of times to get an 18 or 19 digit number (I lost my draft paper). How about the other numbers?