i know that feeling. i learned to skip that question and do everything else. It was painful but I had to shift my thinking to percentages. [greater percentage of correct of the whole test]
ratio – not percentage. I know it’s the same kinda but ratios are more logical than percentages.
2/99 not answered is 97/99 answered – that kind of thing.
[in short, if I can’t do it? Don’t do it. Do everything but that one]
One possibility might be to teach him about negative space.
Drawing a portrait containing everything BUT the figure.
Or imaging air and solid things flipping so that you become air and the air becomes solid.
Anything to think of the “whole room” rather than the “one object” in the room. [that is, the whole test rather than the single question]