Mentor: Look at the number "0.75". What does that remind you of?
Student: It looks like seventy-five cents.
Mentor: Exactly. When a number like 0.75 is written without the dollar sign, it doesn't show money anymore. We call that a decimal. Have you ever heard that word before?
Student: I've heard it when we talk about fractions, but I don't see what that number has to do with fractions.
Mentor: Good point. Let's think about money for a moment. How many cents are in a dollar?
Student: One hundred cents are in a dollar.
Mentor: That's right. How do you write one dollar?
Student: $1.00
Mentor: That's right. The 1 represents the number of dollars, but why do we write the two zeroes?
Student: They show how many cents there are.
Mentor: Exactly. Try to tell me two things that the word quarter makes you think of.
Student: Money and fractions.
Mentor: Exactly. We write one quarter of a dollar as "$0.25". That's in money form, but it's almost the same in fractions and decimals. 1/4 of 1 whole is 0.25 in decimal form.
Student: Where did the 25 come from? I understand in money because a quarter is 25 cents, but 25 has nothing to do with 1/4.
Mentor: That's a really good point, but the 25 actually does have something to do with 1/4.
Student: How? None of those numbers are the same.
Mentor: Why do you think we call the coins that are worth 25 cents "quarters"?
Student: Because 25 cents is one-quarter of a dollar.
Mentor: How do you write one quarter as a fraction?
Student: Oh, I get it. It's 1/4. 25 cents is 1/4 of a dollar. A dollar is 100 cents, so 25 is 1/4 of 100.
Mentor: Right. Decimals just take a fraction use place value to express it. Since there are two places, this decimal is like saying, "what is this fraction of one hundred?" So the decimal form of 1/4 is 0.25. What would be the decimal form of 1/100?
Student: That's easy! 0.01
Mentor: You're exactly right. Now I think you're ready to convert more difficult fractions into decimals.