## Wednesday, September 26, 2012

### An Apple a Day . . . Edible Math

News reports recently have been highlighting how Chinese people have been eating more apples—80% more since 2008, according to the U.S. Department of Agriculture. In years past, apples grown in China would be exported for apple juice sold here in the U.S. (We grow and eat lots of apples in the U.S. but most of our apples for juice are imported from China.) However, the demand for fresh apples is now growing in China so they are exporting less and selling more apples in their own country. As a result, apple juice traders are worried about how the rising costs for apples combined with freezes and droughts around the world will affect the supply of apples and drive up the cost of juice. (Read more about apples and China at The Wall Street Journal online.)

In Excel Math, students learn higher-order thinking skills to help prepare them for high school, college and everyday life beyond the classroom. Help your students understand the impact certain behaviors can have on themselves and their own families in our interconnected world. Talk about the potential shortage of apples for juice. Bring apples (and/or juice—see below) for your class to eat after your discussion. If you have an apple slicer, show how it has metal dividers before you use it to cut an apple. Have a student count the number of spaces in the slicer, and let the class estimate how many slices it will cut. Point out that it will also cut out the apple core. Next, have a student count the number of people in the room (students plus teachers and aides).

Ask the class how they would determine how many apples to cut so everyone has at least one slice. Point out that they would divide the number of people in the room by the number of slices to find out how many apples are needed. If you like, have the students calculate how many apples would be needed for each person to have two slices. (Since there may have been some slices left over after calculating the first equation, the most accurate way to decide how many apples are needed would be to divide the number of people in the room by double the number of slices in your apple slicer. The other way to decide would be to simply multiply by 2 the number of apples needed for one slice.)

If you don't have a slicer, ask the class how many slices you would need to make in each apple to share 4 apples among the whole class so each person gets one slice. Then ask how many apples you would need (to give each person one slice) if you cut 6 slices from each apple.

To help your students understand volume, bring a gallon of apple juice, a measuring cup, and small paper cups for your class. Help your students calculate how many 1/2-cup portions could be served from a gallon of juice. (One gallon = 16 cups so a gallon would contain 32 1/2-cup servings.) Then have the students determine how big each serving would be if you divided the gallon evenly among everyone in the classroom. For younger students, make the total evenly divisible by 16 so if you have a class of 30 plus one teacher, add your principal for a total of 32. (If you have 31 students plus one teacher for 32 total people, each serving would be 1/2 cup. If your total number of people is 24, each serving would be 3/4 cup.)

Let your students check their calculations by pouring the amount of juice they determined into the number of cups they mentioned. (If you have 32 total people, each serving would be 1/2 cup. The student pouring the juice could use a two-cup measurer and pour 1/2 cup of juice into each cup. He could pour 4 cups before needing to refill the measurer.)

Enjoy the juice as you talk with the students about other foods they enjoy that might be more difficult to divide evenly. You may also want to include rising costs and/or menu planning as a lesson topic. Here are the answers to the Excel Math Create A Problem Worksheet shown above: