Corn Volumes

Corn Volumes

Target Grade Level / Age Range:

3rd

Time:

45-60 minutes  

Purpose:

Students will work to solve math problems relating to volume, while learning about corn production in Iowa.

Materials:

  • Measuring cup
  • Shelled corn (1 cup/student or small group)
  • An ear of field corn (1 cup/student or small group)
  • Corn volumes worksheet.docx
  • Bushel basket or picture of a bushel basket (optional)
  • Examples of products made from corn (optional)

Suggested Companion Resources (books and websites)

Vocabulary (with definitions)

  • Kernels – corn seeds
  • Ear- the part of the corn plant that holds kernels
  • Husk- leafy outer covering of an ear of corn
  • Yield- the amount of grain produced from a corn plant.
  • Bushel- A unit of measuring grain and grain yield

Background – Agricultural Connections (what would a teacher need to know to be able to teach this content)

Corn can be used for many things, including food, animal feed and fuel.  Field corn is different than sweet corn.  Field corn is used for ethanol production and livestock feed, and is processed into corn syrup, cereals, and corn chips. Sweet corn only has one primary use – human food.  It is sold on the cob, frozen, or canned. 

Iowa is the #1 corn producing state and corn is Iowa’s #1 most produced crop.  99% of the corn grown in Iowa and the U.S. is field corn.

Farmers measure grain in bushels. One bushel is the same volume as eight gallons. One acre (about the size of a football field) of corn can yield upwards of 190 bushels of grain. In 1972, that number was only 116. This chart shows that progress through time. Where the initial uptick is seen in about the 1930s is when hybrids and fertilizers became more commonly used. Since then, genetic modification, advanced technologies, and superior genetics have caused a huge burst in corn production.

Farmers like seeing large ears of corn in their field. This means they can plant less plants and get more yield from each plant. This can help farmers be more sustainable.

Interest Approach or Motivator

Place various items containing corn on display. Products may include diapers, ketchup, cereal, fruit snacks, tortilla chips, candy, cereal, crayons, candles, paper, plastics, and soap.

Ask the students which of the items do they think contain corn?

Tell the students all of these items contain corn! Corn has many different components that can be used for a variety of different purposes.

Procedures

  1. Explain to students that today they will be working with volumes. And corn! Explain that they will each get 1 cup of corn kernels, and a worksheet. They will need to count the kernels in the cup and record it on their worksheet. Have them stop when they finish that step.
  2. Hand out the cups of corn and the worksheets. Allow students to be creative with how they count their kernels (organize in groups of 2, 5, 10, etc.).
  3. Explain to the students that their next task will be to find out how many kernels of corn there are in a bushel! Have a few students guess how many kernels of corn they think might be in a bushel. (If you have a bushel basket or picture of one available to show scale, that could be beneficial.)
  4. Explain to the students that they will be taking small steps to find how many kernels of corn in a bushel. Each question on their worksheet will get them one step closer to the final answer.
  5. Allow students to work at their own pace to find the answers on their worksheet. Walk around as they work to assist and answer questions.
  6. When students reach the end of the worksheet, ask them what answers they got. Get a few volunteers. Note how they might not all be the same, because the cup might have had slightly different numbers of kernels in them. Write some examples on the board and compare to their original hypotheses.
  7. Then, give the students an ear of corn. Instruct them to leave the kernels on the cob. Ask for some volunteers to guess how many kernels are on an ear of corn. Write some ideas on the board.
  8. Have the students flip their worksheet over and begin answering the questions on the back (Kernels per Ear side). Allow them to take notes as they are counting, etc.
  9. When students finish this side of their worksheet, ask for some volunteers to say how many kernels their ear had. Compare to their hypotheses.
  10. Ask the students, did some ears have more kernels than others? Do they think farmers want ears with more kernels or less? Why might that be?
  11. Talk with students about yield and some examples of what a farmer might see in his field. They won’t be measuring corn in cups, but they will measure in bushels per acre! Talk about the size of an acre and how many bushels of corn would come from that.
  12. End the discussion with some takeaway statements from students, and have them turn in their worksheets.

Essential Files (maps, charts, pictures, or documents)

Did you know? (Ag facts)

  • A bushel of shelled corn weighs 56 lbs.
  • The average yield for a corn field in Iowa in 2015 was 192 bushels per acre.
  • An acre is roughly the size of a football field.
  • There are about 90 million acres of corn planted in the U.S.
  • 13.5 million acres of corn were planted in Iowa in 2015.
  • The U.S. produces about 40% of the world’s corn.

Extension Activities (how students can carry this beyond the classroom)

  • Using the information from today’s lesson, find 10 items in your home that contain corn.

Sources/Credits

Author(s)

Phyllis Paulsen

Organization Affiliation

East Mills CSD

National Agriculture Literacy Outcomes

  • Science, Technology, Engineering & Mathematics Outcomes
    • T4.3-5.b: Describe how technology helps farmers/ranchers increase their outputs (crop and livestock yields) with fewer inputs (less water, fertilizer, and land) while using the same amount of space.

Iowa Core Standards

  • Math:
    • 3.MD.A.2- Measure and estimate liquid volumes and masses of objects using standard units of grams (g), kilograms (kg), and liters (l).
    • 3.OA.C.7: Fluently multiply and divide within 100, using strategies such as the relationship between multiplication and division or properties of operations.