15/600 = 2.5%
A fraction like 15/600 can describe a small portion of a larger group, such as 15 defective items in a shipment of 600 or 15 rainy days out of 600 days. That amount is 2.5%, so it represents a relatively uncommon event.
To picture 15/600 quickly, imagine 600 people standing in a large crowd and only 15 of them stepping forward. You can also think of it as about 2 or 3 out of every 100, which makes it easier to estimate at a glance.
A common mistake is to think 15/600 is 15%, because people may focus on the numerator and overlook how large the denominator is. The denominator represents the whole group, so a larger denominator makes the fraction smaller when the numerator stays the same.
