Student groups compete to design a process that removes the most iron from fortified cereal. Students experiment with different materials using what they know about iron, magnets and forces to design the best process for removing iron from the cereal samples.
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- Common Core State Standards for Mathematics: Math
- 2. Measure and estimate liquid volumes and masses of objects using standard units of grams (g), kilograms (kg), and liters (l). Add, subtract, multiply, or divide to solve one-step word problems involving masses or volumes that are given in the same units, e.g., by using drawings (such as a beaker with a measurement scale) to represent the problem. (Grade 3)  ...show
- 3. Draw a scaled picture graph and a scaled bar graph to represent a data set with several categories. Solve one- and two-step "how many more" and "how many less" problems using information presented in scaled bar graphs. For example, draw a bar graph in which each square in the bar graph might represent 5 pets. (Grade 3)  ...show
- International Technology and Engineering Educators Association: Technology
- C. Things that are found in nature differ from things that are human-made in how they are produced and used. (Grades 3 - 5)  ...show
- D. Tools, materials, and skills are used to make things and carry out tasks. (Grades 3 - 5)  ...show
- H. Resources are the things needed to get a job done, such as tools and machines, materials, information, energy, people, capital, and time. (Grades 3 - 5)  ...show
- J. Materials have many different properties. (Grades 3 - 5)  ...show
- K. Tools and machines extend human capabilities, such as holding, lifting, carrying, fastening, separating, and computing. (Grades 3 - 5)  ...show
- C. Troubleshooting is a way of finding out why something does not work so that it can be fixed. (Grades 3 - 5)  ...show
- E. The process of experimentation, which is common in science, can also be used to solve technological problems. (Grades 3 - 5)  ...show
- E. Design is a creative planning process that leads to useful products and systems. (Grades 6 - 8)  ...show
- Next Generation Science Standards: Science
- Define a simple design problem that can be solved by applying scientific ideas about magnets. (Grade 3)  ...show
- Develop a model to describe that matter is made of particles too small to be seen. (Grade 5)  ...show
- Make observations and measurements to identify materials based on their properties. (Grade 5)  ...show
- North Carolina: Science
- Explain that minerals are an important part of the human diet.
- Explain that different minerals have different roles in human health and state some of them.
- Describe why iron is an important part of the human diet.
- List several foods that contain iron.
- Describe why food engineers add iron and other minerals to cereal.
- State that the iron in our cereal is the same iron that is attracted to magnets.
- 480 ml (1 cup) cereal with a high iron content, such as Total® or any cereal that contains 100% of the recommended daily allowance of iron
- magnets of varying strengths, such as magnets generally used in classrooms; refrigerator magnets have less strength and may not work, but provide students with an alternative with which to experiment
- Ziploc® bags
- cups of water
- electronic balance that is sensitive enough to be able to detect small changes in weight (at least one tenth of a gram); if not available, see the Procedure section for alternative ways to quantify the amount of cereal removed
|mineral:||Natural compounds that are important in helping the body perform many vital functions.|
|iron:||A mineral that is necessary to transport oxygen around the body (part of hemoglobin).|
|calcium:||A mineral that is helpful in building strong bodies, especially bones and teeth.|
|potassium:||A mineral that helps to keep muscles and nervous system working well.|
|zinc:||A mineral that helps the human immune system.|
|fortify:||To add one or more ingredients to a food to increase its nutritional content.|
|magnet:||An object or device that produces a magnetic field that attracts other magnets and certain metals.|
Before the Activity
- Gather materials.
- Divide the materials so that each group of two or three students has a set.
With the Students
- Ask students if they have ever read the nutrition labels on their foods. Also, ask them if they ever noticed things such as iron or calcium on the labels.
- Define what a mineral is and discuss some of the important minerals. Have students write down the functions of the minerals defined above and brainstorm as a class what might happen if people do not get enough of the minerals.
- Tell students that iron is often added to cereal products. Tell the students that they are going to design a process to remove the iron from cereal. Inform them that food engineers often do the opposite.
- Divide the class into groups of two or three students each. Vary the groups size depending on class size and material availability.
- Pass out cups of cereal to each group and let them examine it. Have them notice that they cannot see the iron at this point.
- Give the groups 5-10 minutes to discuss their plan to extract the iron from the cereal. Walk around to see if their plans make sense. Do not tell them that their plans are wrong or will not work (yet).
- Have groups gather the materials that they chose.
- Give students about 15-20 minutes to try to extract the iron from their cereal samples. During this time, walk around the room and talk to the groups about what they are doing. Make suggestions for changes if their processes are not working.
- First, give small hints such as, "think about what you could do with the water."
- Second, explain what the different materials will do and how it may help them. For example, tell them that the water helps separate the iron from the cereal and allows it to move.
- If none of these work, begin giving more direct guidance.
- Ask students to weigh how much iron they can remove from their cereal. In order to be able to weigh the iron, first weigh a clean tissue. Then, wipe the iron off of the magnet. Keep the tissue as dry as possible. If the tissue does get wet, allow it to dry and then weigh it again. The weight of the tissue with the iron minus the weight of the clean tissue is the weight of the iron. Note: If a sensitive scale is not available, have students count how many specks of iron they can remove from the cereal. This process is not as accurate, however, it gives students an idea of how much iron is removed from the cereal, which is most important.
- If time allows, give students more time to revise their processes and trade in their previous materials for new materials.
- What procedures worked best when you tried to remove the iron from the cereal?
- Why do you think the blender helped get iron out of the cereal?
- How do you think the extra iron was added to cereals?
- Why do you think certain cereals are fortified with extra iron?
Activity Embedded Assessment
- For lower grades, give students more direction on the iron removal. For example, give them the specific materials that they need to use, that is, a magnet, water, cup, plastic bag for crushing.
- For upper grades, give students less direction or permit them to choose different foods from which to remove iron. For example, simply ask students to remove the iron from a food. Then, give them time on their own to think about what would work and request certain materials (or bring them in).
Dietary Supplement Fact Sheet: Iron. Updated July 26, 2005. Office of Dietary Supplements. National Institute of Health. Accessed April 26, 2007. http://ods.od.nih.gov/factsheets/Iron-HealthProfessional/
Minerals. Reviewed August 2004. Kids Health. Nemours Foundation. Accessed April 26, 2007. http://www.kidshealth.org/kid/stay_healthy/food/minerals.html
Matsui MD, William. MedlinePlus Medical Encyclopedia: Anemia. 2005. A.D.A.M., Inc. Accessed April 26, 2007. http://www.nlm.nih.gov/medlineplus/ency/article/000560.htm
Guidelines for Iron Fortification of Cereal Food Staples. May 2001. Sustain: Sharing U.S. Technology to Aid in the Improvement of Nutrition. Accessed April 26, 2007. http://www.sustaintech.org/technology/iron.htm
© 2013 by Regents of the University of Colorado; original © 2007 Duke University
Engineering K-PhD Program, Pratt School of Engineering, Duke University
Last modified: April 17, 2015