“Why are we doing math in writing class?” a student complained this morning.

“Because we’re working with information, and this information happens to have numbers in it,” I explained. That’s why it makes sense to do math in health class, too, or health in math class, as the case may be. In real life, it’s usual to use a variety of kinds and sources of information for one task, and our students might as well get used to doing so themselves.

With a little math, you can learn a lot about nutrition.

### Understand nutrition labels

There are two nutrition labels in the bowl above. If we compare them we see a couple of fairly similar foods: one has 140 calories in a one ounce serving and the other has 130, not an essential difference for most schoolchildren, and both have a grain as the first ingredient. Here’s a comparison:

Food A | Food B | |

calories | 140 | 130 |

fat | 6g | 0g |

sodium | 55mg | 190mg |

carbohydrates | 19g | 29g |

sugars | 0 | 4g |

protein | 2g | 2g |

Vitamin A | 0% | 25% |

Vitamin C | 0% | 25% |

Calcium | 4% | 0% |

Iron | 2% | 50% |

Fiber | 2.5g | 2.5g |

A has more fat; B has more sugar and salt. A has more calcium; B has more vitamins and iron. They’re equals on protein and fiber. It would be hard, looking at this information, to say that one is a significantly healthier food than the other. And yet we’re looking at the nutritional data for corn chips (food A) and Rice Krispies (food B). Many of us would class corn chips as a non-nutritious fun food and breakfast cereal as a healthy food.

Here’s a fun way to learn to read nutrition labels for processed foods, and also to practice creating and understanding graphs:

- Collect a good variety of nutrition labels from your own kitchen and by asking students to bring some from home.
- Divide the class into two groups and divide the labels between the groups.
- Have students create charts like the one above comparing pairs of foods with “food A” and “food B” as the labels.
- Have the first group present a chart to the second group, challenging them to figure out which food is A and which is B. Then switch sides. You can keep track and make a competition of it or turn it into a classroom game show (Educational Insights Classroom Jeopardy makes this or any classroom game into major TV fun).

**Calculate with recipes**

Recipes are full of math. With recipes you have measurement, fractions, temperature, and time all in one place. Grab a couple of cookbooks or a stack of foodie magazines and do some calculating:

- Adjust a family sized recipe to make enough for the whole class.
- Calculate how many different recipes would be needed to prepare for a class party: for example, see how many cookies each of several recipes makes and determine how many different batches of these cookies would be required to make sure that everyone in the class had two cookies at the party. This gives you a good opportunity to discuss how much a serving ought to be in an era of supersizing.
- Rewrite recipes with healthier ingredients by replacing half the grains with whole grains or reducing sugar by 1/3. Do the math to make sure the proportions work out.
- Let younger students use dry macaroni or rice and measuring cups to practice measuring out ingredients.

Marilyn Burns found that most adults would, if they had to double a recipe that called for 1 and 3/4 cups of water, measure out 1 and 3/4 cups twice rather than attempt the calculation. Challenge your class to overcome this barrier.