Imagine a question and stream-of-consciousness explanation for which this is the answer: 900
Question: 5,000 people live in a small town. 2,000 males live in that town and the rest of the population are females. Thirty percent of the female population wears glasses. How many females wear glasses?
Stream-of-consciousness: There are 5,000 - 2,000 = 3,000 females that lives in the town. Since thirty percent of the female population wears glasses, 30 / 100 * 3,000 = 900 females wear glasses.