 ## Piggy Bank Math

Mathematics, Operations (+, -, x, /, etc.), Problem Solving

### Objective

Students use coin values to solve problems.

### Directions

Introduce the lesson by showing students a variety of coins and coin combinations.

• Bertha Biggspender broke open her piggy bank.
• She had a total of seven coins worth \$0.19.
• Which coins did she have?

To solve problems of this type, you need to know three things:
• the number of coins
• the total amount of money
• any kinds of coins not included

Pennies First
Always do the pennies first in these problems. To have \$0.19, Bertha had to have at least 4 pennies because pennies are the only coins which could be used for the last four cents. This leaves \$0.15 to be accounted for and three remaining coins. The only coins which will work for this combination of money are three nickels.
Make a Chart
Record the information on a chart like this:

 Number of Coins Amount of Money 4 pennies \$0.04 3 nickels \$0.15 Totals: 7 coins \$0.19

Challenging Problems
Bertha Biggspender found her wallet which had seven coins worth \$0.91.
She did not have any dimes or half dollars. Which coins did she have?
Do the pennies first--she had to have at least one penny. There were not enough coins to have more than one penny. She has six coins which equal \$0.90. She had no dimes and no half dollars so the combination must include only quarters and nickels. A total of three quarters and three nickels will work.

 Number of Coins Amount of Money 1 penny \$0.01 3 quarters \$0.75 3 nickels \$0.15 Totals: 7 coins \$0.91

Reminders
• Make a chart.
• Do pennies first.
• Do not forget half dollars.
• Match exact number of coins.
• Match exact amount of money.

### Resources

• Piggy Bank Math activity pages
• pencils