## Popping Up Percents!

### Annette NixonSanta Rosa District Schools

#### Description

Popcorn provides a tasty way to practice finding percents and unit price.

#### Objectives

The student selects the appropriate operation to solve problems involving addition, subtraction, multiplication, and division of rational numbers, ratios, proportions, and percents, including the appropriate application of the algebraic order of operations.

The student adds, subtracts, multiplies, and divides whole numbers, decimals, and fractions, including mixed numbers, to solve real-world problems, using appropriate methods of computing, such as mental mathematics, paper and pencil, and calculator.

The student uses estimation strategies to predict results and to check the reasonableness of results.

The student uses direct (measured) and indirect (not measured) measures to compare a given characteristic in either metric or customary units.

The student selects and uses appropriate instruments, technology, and techniques to measure quantities in order to achieve specified degrees of accuracy in a problem situation.

#### Materials

-Volunteer or microwave in classroom
-One bag of microwave popcorn per group (variety of brands)
-Triple beam balance
-Paper towels
-Worksheet (one per student)

#### Preparations

1. Copy worksheet. (One per student.)
2. Prepare a chart for the overhead or board, including spaces for group number, counted percent popped, weight percent popped, and unit price for each group.
3. Gather materials.
4. Pop a bag of popcorn for each group.
5. Divide class into small groups.

#### Procedures

1. Discuss comparison shopping with the class. Microwave popcorn, for example, comes in many varieties. Many factors such as taste, price, and previous performance are taken into account. Mention that there are companies which do this professionally.

2. If this is a practice activity, review quickly how to find percents and unit price, being sure to remind them to use the totals when finding percents. For example, if 110 kernels popped and 20 did not, to find the percent popped, they would be finding 110 is what percent of 130 (total). This may be used to introduce percent and unit price, but direct instruction will be needed at each step.

3. Have students follow instructions on the worksheet, each filling out their own worksheet, while working together to weigh, count, and calculate.

4. Have each group record their findings on the chart on the overhead. They will need all of the results to answer questions #4-7.

#### Assessments

Assess informally as students are working on the activity by circulating thoughout the room. Collect worksheets to check students' mastery of finding percents and unit price.

#### Extensions

For other ideas using popcorn, visit the following Website (www.popcorn.org). They will send a teacher's guide.