Science centers encourage cooperative work groups. Elementary teachers may want to conduct lessons during those weeks when students’ attention spans wane; such as before major holidays, etc. In middle school science, students are randomly selected to teams so that group members are new each time. This eliminates having that one lonely student who has not been chosen. Typically one week of centers is designated per unit. On Day One, centers are introduced and explained. Students are given 15 to 20 minutes to work in each center. Typically 8 centers are assigned to keep the number of students in each work group small. One assignment is included using a computer. If you don’t have a student computer station you may want to check one out of the library. This unit has many activities to select from.