What is 9/18 as a percentage? It is 50.00%.
The fraction 9/18 can be reduced by dividing both the numerator and denominator by 9, giving the simpler form 1/2. A half always represents half of a whole, which is the same as fifty percent.
Think of it like cutting a pizza into two equal slices. If you eat one slice, you have eaten 50.00% of the pizza. The same idea works for any situation where something is split into two equal parts.
In short, 9/18 and 1/2 both mean the same thing, and they both equal 50.00% of the whole.