Estimating Large Numbers

What does a million look like? In this activity students experience large numbers by estimating the number of grass blades in a field.

DIVIDE the class into groups of four students with the following roles:

• Materials Handler: Distributes materials.
• Equipment Handler: Manipulates materials.
• Recorder: Records results.
• Speaker: Shares results with the class.

Materials Handlers PASS OUT four dowels and four rubber bands to each group. Equipment Handlers MAKE a square, using the rubber bands to connect the corners.

Class GOES outside to a field of grass. Equipment Handlers PLACE the dowel square where the group wants to work. Group members each COUNT the grass blades inside a section of the square. Recorders WRITE the number of blades each student counts on the data collection sheet.

Equipment Handlers WALK the square along each side of the field to determine its length and width. Recorders WRITE the length and width of the field on the data collection sheet.

Speakers FILL OUT the data collection sheet to determine the total number of blades of grass in the field. SPEAKERS report their results to the class. COMPARE each group's results.

We used this method at the Miami Museum of Science. Our field is about 3,600 square meters and there were about 1,300,000 blades of St. Augustine grass.

What's Happening? Find out more about large numbers and pH.

Challenge. How many truck loads of jelly beans would it take to illustrate the National Debt? About 100,000 jelly beans will fit in a truck, and one jelly bean equals one dollar. Share your ideas in the pH Exchange.