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Uses proportional thinking (e.g., rates, scaling, similarity) to solve problems.

Square Root of 2: Irrational, Yes! Impractical, No!

For the mathematically inclined person, irrational numbers such as a2 are fascinating, both from a historical perspective, and as a classic example of using the reductio ad absurdum proof, to prove the irrationality of a2. However, the majority of students, when introduced to the irrational number a2, might be excused for not being fascinated by it, and might believe that a2 has not much practical use.

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