Im not sure exactly what youre asking but I will give an example.
4 divided by 1/4
4/1 times 4/1 you flip the second term and switch to multiplication
numerator: 4 times 4 = 16
denominator: 1 times 1 =1
the final answer would be 16
to check this you multiply 16 times 1/4 and you would get 4