A fraction is bigger or smaller depending on the numerator and denominator.
For example, 1/2 is larger than 1/4 because a half is larger than a quarter. This means that the larger the number underneath, the smaller the number.
But, this can change if the numerator (the number on top) is different than one.
For example, 3/4 is greater than 1/2 because three quarters is more than a half. (two quarters is equal to a half)