24/66 as a percentage is 36.36%. This value tells you how much of a whole the fraction represents when expressed in a more familiar form.
The fraction 24/66 can be reduced to 4/11, which still keeps the same value. Seeing it as a percentage makes it easier to compare with other numbers that are already in percent form.
Percentages are handy in everyday situations—like figuring out discounts, grades, or statistics—because they show a part of a whole out of 100. Knowing that 24/66 is 36.36% lets you quickly understand its size in that common scale.