Video

Percent word problem: 78 is 15% of what number? (Full video)

Khan Academy

Supporting grades: 6

Description: In this example, you working with us to find the number that is expressed as a given percentage. We'll create a simple algebraic equation to solve! Created by Sal Khan and Monterey Institute for Technology and Education. So let's just call that unknown number x. Now, 15% mathematically, you can deal directly with percentages, but it's much easier if it's written as a decimal. So we could rewrite this as 0.15 times some unknown number, times x, is equal to 78.

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