###### Alissa Fong

MA, Stanford University
Teaching in the San Francisco Bay Area

Alissa is currently a teacher in the San Francisco Bay Area and Brightstorm users love her clear, concise explanations of tough concepts

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# Addition and Subtraction with Decimals - Problem 3

Alissa Fong
###### Alissa Fong

MA, Stanford University
Teaching in the San Francisco Bay Area

Alissa is currently a teacher in the San Francisco Bay Area and Brightstorm users love her clear, concise explanations of tough concepts

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If we know how fast three swimmers out of four have gone, and we know the swimming relay goal, we can figure out how fast the last swimmer must go in order for the relay to break the record. First, add up the first three swimmers to see how much time has already been used. Then subtract that sum from the goal time to see how many seconds are left for the final swimmer. You need to be careful with units- make sure all of your numbers are in minutes or all in seconds or whatever unit you choose.

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