When determining which fraction from a set of two fractions is bigger or smaller, one must first check to see if both denominators are the same numerical value. In this case, both denominators are 9, so we can skip the first step.
Now completely ignore the denominators and focus on the numerators; pretend the denominators do not exist. Next, ask yourself: Which is larger, 5 or 8? In which the answer would be 8, so therefore, 8/9 is greater than 5/9.