Redo calculations if necessary. Assignment Students recalculate radii and circumferences, underestimating each shadow by one millimeter. Ask them to look for the pattern of error introduced for various-sized fruits. This will show that students have mastered the basic formula of Eratosthenes' method. Assessment Check journals for accuracy of sketches and measurements.
Students visit websites and answer questions on worksheet.
Students print out a table of results from schools around the world for use in their homework assignment. Flag each participating school on world map. End Modifications Supervise students to be sure they can and do locate websites. Assignment Estimate the earth's circumference by calculating the average circumference from all schools. Cross out the outlying circumferences.