Common Core Standard: 7.RP.1.1 - Unit Rate Problems that involve fractions, decimals and whole numbers. It also requires them to convert units (i.e. minutes to a fraction of an hour, or inches to a fraction of a foot).
I teach my students what has proved to be a helpful 3 step method of writing out the rate in words first, then replacing the words with the numbers from the problem, then solving. This has helped them slow down and understand which number has to be the numerator and which number has to be the denominator.