Either option costs one class period. However, the former method will require a large degree of additional work outside of class to achieve the same degree of learning the latter provides at one sitting. The choice is yours. Successful students have legitimate goals and are motivated by what they represent in terms of career aspirations and life's desires. If your educational goals are truly yours, not someone else's, they will motivate a vital and positive academic attitude.
Successful students ask questions to provide the quickest route between ignorance and knowledge.
In addition to securing knowledge you seek, asking questions has at least two other extremely important benefits. Think about it. If you want something, go after it. Get the answer now, or fail a question later. There are no foolish questions, only foolish silence.