At least 50% of the math that you end up doing in your real life will involve percentages. We're not really sure about that figure, but it sounds authoritative. Anyway, unless you've watched this tutorial, you're really in no position to argue otherwise. Common Core Standards: 7.EE.B.3
868_Percent_word_problem_100_is_what_percent_of_80_.html
867_Solving_percent_problems.html
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