90/100 = 90%
The fraction 90/100, or 90%, shows up in everyday life when something is nearly complete. For example, a phone battery, a test score, or a project might be described as being at 90 percent.
You can picture 90/100 as 90 shaded squares in a grid of 100, leaving only 10 unshaded. A quick estimate is to think of it as nine out of every ten, which makes it easy to recognize as a large amount.
A common mistake is treating 90% as the same as 90 whole items, even though it depends on the total amount. Ninety percent of 10 is 9, while 90% of 1,000 is 900.
