That's true, but usually they get their method right (or close to it) but fail on the simple addition. If you use it to help figure out what steps you need to take, you can then run through substituting the correct numbers in and make some real progress.

I just completed a class on hydrology and water engineering with this method. Got a HD. That either says something about the school or something about GPT. Not sure which.

It certainly says something about my willingness to complete water engineering coursework, I'll admit that.