Whether you should cook the whole package of bacon or use just the strips you need for a recipe depends on your personal preferences and intended use of the remaining bacon.
If you have a specific recipe that requires a few strips of bacon, you can certainly cook only the number of strips needed for that particular dish. This approach helps you avoid wasting food and ensures that you're using fresh bacon for your recipe.
However, if you enjoy bacon and anticipate using it for other purposes, you might consider cooking the entire package. Cooked bacon can be stored in the refrigerator for a few days, or you can freeze it for longer-term storage. Having pre-cooked bacon on hand can be convenient for quick meals, sandwiches, salads, or other recipes.
Ultimately, the decision depends on your cooking habits, storage capacity, and how frequently you use bacon. Just ensure that you store any cooked bacon properly to maintain its quality and prevent foodborne illnesses.