Lesson 3 of 7
Objective: SWBAT use an understanding of multiplication, division, grams, and portion sizes to research and round the average amount of protein in servings of common foods, including vegetables. They will represent this information on a scaled pictograph.
This short introductory video asks students to think of 3 foods they associate with the word protein, and asks them if they think that beans and vegetables have protein. They write down their 3 protein foods in the Powerful Protein opener.
The purpose of the guided practice is threefold.
First, I want students to review rounding decimals in the hundredths or tenths place to the closest whole number. I write the decimal values in fraction forms.
Secondly, I discuss typical portion size with students and explain that in this activity it isn't what THEY eat or what a person SHOULD eat, rather the amount of this given item the students might see on an average kid's plate if they enter a restaurant.
Finally, we will discuss the pictograph model used for hamburgers and hot dogs and as a class will create simple symbols for the remaining foods and convert the data into pictograph form.
Note: Make certain that when you work through how to create a symbol for bacon, you guide students into writing 1/4 of that symbol on the paper to represent 0.5 grams of protein in bacon, since each symbol represents 2 grams.
Here, a student explains how to divide a symbol in half to represent a quantity in a pictograph.
In this part of the lesson, students collect data about the protein content of common vegetables. The portion size in these examples is 100 grams, which is equivalent to 3.5 ounces. An easy to access frame of reference for the students is a can of beans (plain beans) that weighs 15 ounces. This is equivalent to 425 grams or 4 1/4 100 gram servings. I tell the students that the can is 400 grams, rounded to the closest hundred.
While or after recording the data on the table, students can decide on a symbol for each vegetable. I intentionally set the increments as 2 grams of protein so students could reason through how to represent odd numbered amounts of protein grams. (Half a symbol).
Then they fill out the pictograph with their symbols, give the pictograph a meaningful title, and make a key. I discourage them from including every symbol on the key as that's not necessary or efficient. All the viewer needs to know is that the symbols represent units of 2 grams.
If students do not have internet access during this lesson, this document (Basic Vegetable Data) compiled from Wikipedia contains protein information for common vegetables.
The first 5 pages of What Color is Your Food? have an extensive list of fruits (next lesson) and vegetables if students want to look up items beyond the most common choice
Here are two online resources for students to use to research these data on their own:
(the protein data is in the column immediately to the right of the picture)
For the purposes of this activity, I include fruits (zucchini, tomatoes, cucumbers), and fungi (mushrooms) in the vegetable categories because that is the common reference. Of course, a seed-bearing body is a fruit and mushrooms are not a plant!
I let students know ahead of time that this question is not as easy as they think it is. I use the word "trick" sometimes because they seem to like it, but am clear to define it as something that is deceptively simple, not an attempt to fool them. By cuing them to think more deeply, they are geared up for a higher level of thinking and the "trick" aspect is actually defused.
This is my closing question for the lesson.
I tell the students that physicians and nutritionists from a wide range of backgrounds all agree that protein is an important component of a person's diet. I give them an admittedly approximate amount of daily protein needed in the diet of an average 3rd grader. (35 grams*) Then I ask students to think and then either write down (in their math journals) or discuss, which foods are the best way to get protein? If they had to eat only vegetables, which ones would be the best ones?
Students think the same as most people in this regard, it is in our nature, that what appears to be the highest number is automatically the best. Of course, it is far more complex than that, because 100 calories of kale nutritionally very different from 100 calories of hamburger, and very few people sit down and eat only 100 calories of hamburger while many people eat very few calories of green leafy vegetables because the portion size for 100 calories of each is so different.
Additionally, there is much debate in the nutrition and medical community about which foods provide protein that is most easily absorbed by the human body. Some people theorize that protein is best absorbed from meats. Others theorize that protein is best absorbed from vegetables. This is not an issue that needs to be resolved in 3rd grade, but they can and should be exposed to the fact that numbers alone often do not provide enough information. Mathematical reasoning and the ability to critique the reasoning of others is required in order to develop a big picture understanding of data, in any setting. Nutrition is just a relevant and visible example.
*(I set this number based on the recommendation of 45 grams a day for a sedentary adult woman - it is not a scientific number).