I always state the number of points possible on exam problems. If you have this practice, then take it a step further. Suppose a 10-point problem says:
Find the volume of the rectangular prism shown below.
Ask yourself what you want to see a student do. In my class, I would want (based on class demonstrations, homework problems, etc.) them to write an expression that involves a basic formula (no numbers), followed by that expression where the particular lengths have been substituted into that formula (using the correct units), followed by the answer they obtain from their calculator, concluding with the correctly rounded answer, according to the significant digits given (again, with the correct units).
Instead of writing [10 points], I will often write something like [Correct numerical answer = 7 points, Correct units throughout = 1 point, Showed the formula = 1 point, Correctly rounded = 1 point]. This has the benefit of giving me a rubric to follow and publishing that to the student. If you're demonstrating all of these steps in class and awarding/withholding points for them consistently on homework/quizzes, then seeing this breakdown given on the exam should make sense to your class.