66/78 as a percentage is 84.62%. This number tells you how much of a whole the fraction represents when it’s expressed in a way that’s easy to compare with other percentages.
The fraction 66/78 can be simplified by dividing both the numerator and the denominator by their greatest common divisor, which is 6. That gives you 11/13, a simpler form that still equals 84.62% when turned into a percentage.
Knowing the percentage makes it quick to see that the fraction is well over half but still short of a full 100%. It’s a handy way to understand the size of the part compared to the whole in everyday situations.
