Student Worksheet Questions 
Score (points) 
A: Estimate the
circumference of the Earth using Eratosthenes' calculations 
1. Circumference of the earth in
kilometers: 46,350 km
6 
4 
2 
Answer is correct and
student writes all calculations 
Answer is correct and
student writes some of the calculations 
Answer is correct w/o
calculations OR answer may be incorrect but simple
error made in calculations 

____/6 
2. The answer should provide a
thorough explanation in the students' words and include at
least one proposed method to repeat Eratosthenes' experiment
today .
6 
4 
2 
Provides clear & organized
explanation using supportive facts. 
Provides explanation using
supportive facts. 
Provides explanation. 

____/6 
B: Estimate the
circumference of the Earth using Eratosthenes' method 
1. Eastlake, OH, USA
Circumference (estimate): 26,640 km
Percentage Deviation: 33.4% 
____/6 
2. Offenburg, Germany
Circumference (estimate): 31,612.8 km
Percentage Deviation: 21.0% 
____/6 
3. Balgowan, South Africa
Circumference (estimate): 41,251 km Percentage Deviation:
3.1% 
____/6 
4. Adelaide, Australia
Circumference (estimate): 40,694.5 km
Percentage Deviation: 1.7%

____/6 
BONUS: The answer should
provide a thorough explanation in the students' words.
Students should realize that the greater distance between
the two cities results in a smaller percentage error because
a greater central angle results in fewer 'earth slices' with
more room for error in the angle measurement.
3 
2 
1 
Provides clear & organized
explanation using supportive facts. 
Provides explanation using
supportive facts. 
Provides explanation. 

____/3 
Total: 
____/36 