Question

How do you know if 2/3 is in simplest form

Answer 1

There can be 2 ways. One is that the digits of the numerator and denominator are consecutive. And the other one is that either the numerator or denominator is a prime number.

Answer 2

If you cannot divide the numerator and denominator by the same number, then you are done dividing and the fraction is in simplest form.

EXAMPLE:
4/8 = 2/4 = 1/2
I divided 4/8 by 2 and I divided 2/4 by 2 to get 1/2, which the numerator and denominator cannot be divided by the same number. So I'm done.