This is a Prezi that goes through a brief introduction to the History of the Spanish Language. It works wonderfully at the beginning of Spanish 1, for students to see a historical and geographical context to the language. A good option is to have students create a timeline of the language in their notes while you are teaching, using this presentation.
Prezi about the Fibonacci Sequence- Talks about ways that it is seen in nature, Leonardo of Pisa and his bunny problem, Binet's Formula, and the recursive rule.
Prezi on Scheduling that discusses processors, tasks, processing times, precedence relations, optimal schedule, Diagraphs, Precedence relations, and scheduling using a priority list.