Can You Explain It?

Mathematics is just about getting the right answer to problems. It's also about knowing the strategies that tell you how to get the right answer, and knowing when to how to choose the right strategy. (It's also involves recognizing if your first method is incorrect and finding a second method, but that's for another day.)

THINK about the questions below. What approach would you use to solve these problems.

1) You have a quarter and a dollar bill. You owe your friend twenty cents.
Can you pay him what you owe him or not? Explain.


2) Your friend tells you that I can't give you change from the quarter, but he can give you change of your dollar. Does that make sense?