Use Your Knowledge of English: 

1. Analyze the Units of the Answer. How many dimensions?

If the sun is 93,000,000 miles from the Earth, how many kilometers is the distance? (Given: One mile equals 1.61 kilometers.)

kilometers is a length unit: a single (simple) dimension!

2. Is there a single dimension 'number and unit' not connected to a Unit Factor in the problem?

"93,000,000 miles" is also a single dimension
of length which can be connected to the Answer unit!

3. Equate the given to the unit asked for in the answer.

_???__kilometers = 93,000,000 miles