How do you make a fraction in simplest form when it prime?

Answer 1

If either the numerator or denominator is prime, you need to check that the other is not divisible by that prime. If it is then the prime is a common factor and the fraction simplifies either to a unit factor or an integer. Otherwise, there is no simplification possible.

For example, consider the prime 7.

7/21 = 1/3 is a unit fraction.

63/7 = 9 is an integer.

22/7 and 7/22 cannot be simplified.

Answer 2

If the GCF of the numerator and the denominator is 1, the fraction is in its simplest form.