Background Information

Most of the corn we grow in the U.S. is dent corn (also called field corn). While a small portion of dent corn is used for corn cereal, corn starch, corn oil and corn syrup, dent corn is a grain used mostly for livestock feed and ethanol production. You could cook and eat both sweet corn and dent corn as corn on the cob, but the dent corn won’t be as sweet and juicy.

Activity

This activity is designed to reinforce the concept of how to calculate mean, median, mode and range on an ear of field corn. If you have access to multiple ears, you may use them, but for this activity we will provide the data from three ears of corn.

The number of kernels on an ear of corn varies depending on many factors during the growth process. Water, sunlight, soil nutrients, temperature, humidity and other factors are all important as corn is developing. Before beginning the activity have students answer the questions in the Prior to Beginning the Activity section on the worksheet.

Math Review

Mean
Is the average of a data set. You add up all the numbers and divide by the number in the data set. Ex:( 3, 5, 2, 7)…3+5+2+7 = 17….17 divided by 4, Answer is 4.25

Median
Is the middle number in the data set. The numbers have to be listed from least to greatest. The middle number is the median.

• Even example – 2, 3, 5, 7…. Since we have an even number in the data set, take the middle number 3 and 5 add them then divided by 2….3+5 = 8…..8 divided by 2, Answer is 4.
• Odd example – 2, 3, 5, 6, 9 …. Since we have an odd number in the data, take the middle number. The median is then the middle number, Answer is 5.

Mode
The mode is the number that appears the most. In the above examples the mode is 0. In the following data set 2, 4, 4, 5, 9, Answer is 4.

Range
The range is the difference (subtraction) between the largest and smallest number. In the data set 2, 4, 4, 5, 9 ….the range is 9-2 = 7, Answer is 7

Materials

• corn data sheet
• pencil
• calculator
• corn worksheet
• Counting Kernels PowerPoint
• Counting Kernels for Calculating Corn Yields Worksheet

Directions

Use the Corn Worksheet to complete the following. The PowerPoint Presentation will also assist with this activity.

1. Mean or Average: Add up the number of kernels for corn cob #1, then take the total number of kernels in cob #1 and divide by the number of rows. Next, round to the nearest hundredth. Record your answer. Do this for corn cob #2 and corn cob #3 and record your answers.
2. Median: List all the numbers in corn cob #1 in order from least to greatest. Find the middle number in the list. If the cob has an even number of rows take the two middle numbers add them together and divide by 2. Do this same for corn cob #2 and corn cob #3.
3. Mode: Look at the numbers you listed for the median and find the number that appears the most that is the mode.
4. Range: Take the smallest number in corn cob #1 and subtract it from the largest this will get you the range. Do the same for corn cob #2 and corn cob #3.

Supplemental Worksheet

Watch the Counting Kernels video by Bill Johnston and complete the Counting Kernels for Calculating Corn Yields worksheet.

Answer Key

Answers to the worksheet problems can be found on the PDF of the lesson.