## Lesson #18 - Canceling, Permutations and Factorials

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Note: Practice competitions are meant for use in a second one-hour class
on a weekly basis. They are fun. They reinforce recently learned concepts and give
students practice working in teams. Practice competition subjects conform
to the
Washington State Essential Math Learnings concepts namely:
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- Number sense
- Measurement
- GeometricSense
- Probability and Statistics
- Algebraic Sense

Practice competitions also will teach students the concepts of problem
solving, reasoning, communicating, and making connections. All these
concepts conform to the NCTM Mathematics
Standards.