Illuminations: Big Math and Fries

# Big Math and Fries

 We are lucky to live in an age where there is a lot of nutrition information available for the food we eat. The problem is that much of the data is expressed in percents and some of those percents can be misleading. This lesson is designed to enlighten students about how to calculate percent of calories from fat, carbohydrates, and protein. The calculations are made to determine if a person can follow the Zone Diet with only McDonald's food items.

### Learning Objectives

 Students will: mathematically analyze the food they eat. identify the relationship between nutrients and the calories. perform calculations, including percents and conversions.

### Materials

 McDonald's nutrition facts (or any fast food chain) Computer with Internet connection (optional) Calculators Big Math and Fries Activity Sheet

### Questions for Students

 Were you able to stay under 30% for total calories from fat? Do you feel that you designed a healthy day of eating? [Answers will vary] What steps did you take in order to meet the requirements of 2,000 calories total and a 40-30-30 ratio? [Answers will vary. What you're looking for are the strategies that students used to try to balance the results. For instance, did successful students focus on one nutrient, get the appropriate percentage and then change one food item to balance the other nutrients? Did they first calculate the total amount of grams needed for each nutrient base on a 2,000 calorie diet and then work backwards? Or did they come up with something new and unique?] If you were not able to meet the Zone Diet requirements of 40-30-30, could you tweak a few items to change that? If so, which items would you change and how does that improve your carbohydrates-protein-fat ratio for the day? [Students should look at nutrient percentages that are too high and try to figure out which items they could remove or replace in order to get better ratios.] Would it be easier to design one Zone friendly meal and, if so, which items would you choose? [Yes, it would probably be easier to design just one meal to meet the ratios. This should lead students to think about balancing nutrient ratios when they go to eat a meal or a snack.] If you were to design the McDonald's nutrition pamphlet, what would you change from the current design? [Answers will vary. One suggestion might be to provide percentage of each nutrient, not just fat.]

### Assessment Options

 Ask students to design a single meal and see how close they can get to the 40-30-30 ratio. Allow students to design a day's meals using any food they choose to meet the Zone Diet. Students should gather their own nutrition information and provide calculations for how they met the diet's restrictions. Remove the caloric restriction from the activity. Just using the Zone Diet restrictions, is the activity easier, harder, or the same?

### Extensions

 Watch the movie, "Supersize Me," with the students and discuss how the movie relates to the lesson. Have students explain whether or not the movie was a fair representation and why. If your students are familiar with sampling and statistical analysis, you may also discuss the experimental model used in the movie. Talk to a health or physical education teacher and see if they have a unit on nutrition where this lesson could be used as a complement. This lesson is well suited for a spreadsheet application or a graphing calculator program. A spreadsheet application might take the grams of each nutrient for each desired item and automatically calculate the percentage of calories. Students could then more easily use trial and error to find the desired ratio of nutrients for a particular meal. This is only recommended in a class familiar with spreadsheets or graphing calculators.

### Teacher Reflection

 Were most students able to adjust their food choices to achieve Zone proportions? If not, what problems did they run into? How could these problems be avoided? Were any students confused about the difference between calculating the calories due to the nutrient weights and calculating the percent of calories from a particular nutrient? If so, how could this confusion be avoided in the future? Were students motivated to achieve Zone proportions or did they just pick various menu items to get the work part over with? Did students feel that this lesson was interesting or of use to them?

### NCTM Standards and Expectations

 Number & Operations 6-8Work flexibly with fractions, decimals, and percents to solve problems. Understand and use ratios and proportions to represent quantitative relationships. Develop, analyze, and explain methods for solving problems involving proportions, such as scaling and finding equivalent ratios.
 This lesson was prepared by Michael Weingarden as part of the Illuminations Summer Institute.

1 period

### NCTM Resources

 Navigating through Number and Operations,6-8

### Web Sites

 More and Better Mathematics for All Students
 © 2000 National Council of Teachers of Mathematics Use of this Web site constitutes acceptance of the Terms of Use The National Council of Teachers of Mathematics is a public voice of mathematics education, providing vision, leadership, and professional development to support teachers in ensuring mathematics learning of the highest quality for all students. The views expressed or implied, unless otherwise noted, should not be interpreted as official positions of the Council.