# Subtraction in the Real World

## Activity: Making Change

Suppose you have $25.90 in cash (two$10 bills, five $1 bills, and nine dimes) and you owe a friend$16.87. How will you break the $25.90 in order to pay off your debt? ### Discussion Start with the$16.87. You can give your friend a $10 bill. What will you still owe her? ### Answer After giving your friend$10, you will still owe her . You still have five $1 bills, so you fork those over, too! Now you only owe her . Since your friend won’t budge, you need to make change for your remaining$10 bill. Let’s say you break it into a $5 bill and five$1 bills. Then you hand over \$1 to your friend.

At this point, your debt is now . After giving your friend eight dimes, the amount you still owe is .

Taking your last dime and trading it for a nickel and five pennies, you hand over the last 7 cents you owe. Now you’ve erased your debt!

Subtracting One Number from Another