I used to work in a school system where numerical answers weren't required in physics. Usually, the only reason you'd calculate a numerical answer was to help you check it for reasonableness. If you calculated a wrong numerical answer and didn't explain it, then your grade would be lower than if you had just stopped at the formula.
If a question asked you to compare two machines to see which produced the most power, you'd get a top grade writing a symbolic inequality and pointing out in words that some factors are common so they don't affect it, but one of them has an x^2 while the other only has an x, so that for large values of x, that one produces more power, while for small values of x, it's the other one. You'd get a lower grade for calculating two numerical results and identifying the bigger one.
If a question asked you to compare two machines to see which produced the most power, you'd get a top grade writing a symbolic inequality and pointing out in words that some factors are common so they don't affect it, but one of them has an x^2 while the other only has an x, so that for large values of x, that one produces more power, while for small values of x, it's the other one. You'd get a lower grade for calculating two numerical results and identifying the bigger one.