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.
