Checklist for Job assignments: 

1. Job assignments (one data recorder, two direction assistants, one presenter) in the cooperative groups should be changed. 
2. The group should cohesively select 3 items to use for measuring the spheres (i.e. plastic links, large and/or small paper clips, unit blocks, rulers etc.). 
3. The direction assistants take turns making the measurements. 
4. The recorder documents the data on worksheet A as the measurements are being taken.
5. The group collaborates on discoveries they made that are supported by the data.
6. Answer the following question:  Why does the same sphere have different measurements in this activity?
7. Place the spheres in size order. 
8. Compare data from activity 2 to the current data. 
9. Match the spheres to the planets using the data from activities 2 & 4 and combine with the comparative planet size information from http://ic-www.arc.nasa.gov/ic/projects/bayes-group/Atlas/size/Earth/
10. The group decides how to present the data to the class. 
11. The presenter makes the presentation.