Negative Numbers Discussion


Student: What's a negative number?

Teacher: Well let's say you have 0 dollars and I have 10 dollars. You want to buy a game the costs 5 dollars. Do you have enough money to buy the game?

Student: No, but what does that have to with anything?

Teacher: Give me a second. Do I have enough money to buy the game?

Student: Yes.

Teacher: So, if I were one of your friends you could borrow 5 dollars from me to buy the game right?

Student: Yes.

Teacher: Now, let's say I lend you the five dollars and you buy the game. How much money do I have?

Student: 5 dollars.

Teacher: How much money do you have?

Student: None.

Teacher: No, you have negative 5 dollars, because not only do you not have any money; but you owe me 5 dollars.