To begin this lesson, I ask students to work with their science teams to brainstorm a list of healthy foods and a list of unhealthy foods. I ask the students to consider what makes a food healthy or unhealthy. I provide students with five minutes of student talk time. During this time, I ask each group to generate a list of healthy foods and unhealthy foods at their table group. After the group discussion time, I ask students to share their lists with the class. I record the students' answers on the board.
Next, I distribute a copy of the food labels lab recording sheet to each student. I also hand out a food label to each child. I ask them to predict whether their food is healthy or unhealthy and to provide a reason for their thinking in the hypothesis section of the lab sheet. I then ask students to review the food label. I ask them to identify where they could find each of the four nutrients (protein, fat, starch, and glucose) that they tested for in the previous labs. I also ask them to review the vitamins and other nutritional information found on the label.
In this lab, students record observations in narrative form and this is something with which my students have little experience. To help guide them through this process, I model recording observations on a lab sheet using my document camera. I demonstrate what kinds of information they could include on their lab sheet. I also show them how to use their observations to create a conclusion.
I then provide students with 10-15 minutes of time to review the food label and record their observations, and draft a conclusion about the healthiness of the food.
A photo of a student's completed lab sheet can be found here.
After each student has completed their lab sheet, I provide time for the students to share which food they looked at, whether they determined that it was healthy or unhealthy, and what information from the label they used to make this determination. This allows students to compare and contrast their own reasoning with that of their peers. I try to provide more than one student with each food label so that the class can hear two different opinions on the same food.
To allow me to randomly select students for sharing, I create a container which has a popsicle stick for each student labeled with his or her name. I select students for sharing by drawing a popsicle stick from this container. The possibility that they might have to share helps to hold students accountable for using their lab time effectively. Randomly selecting students to share also helps us to hear a variety of perspectives.
A video of my students sharing their conclusions can be found here.