"Samantha earns $22 per hour, how much does she earn per minute in cents?"
1) What conversion factors would you use?
2) What is the answer?
Notice that the fractions are set up so that the units cancel: there is "dollars" in the numerator of the first fraction and in the denominator of the third fraction-they "cancel". There is "hr" in the numerator of the second fraction and in the denominator of the first fraction- they "cancel". That leaves "cents" in the numerator and "min" in the denominator: "cents per minute".