Final answer:
The next step after implementing a strategy in problem-solving is to determine if the answer is reasonable and identify the cause if it is not.
Step-by-step explanation:
The next step after implementing a strategy in problem-solving is to determine if the answer is reasonable and identify the cause if it is not. This step ensures that the solution aligns with the given problem and its requirements. One way to do this is by comparing the answer with known values, checking if it falls within a reasonable range, or using estimation techniques to validate the answer. For example, if a problem asks for the number of books in a library, and the answer is a negative number, it would be clear that the answer is not reasonable.