What you will probably find is that if you are given a "straight forward" question (you are given the true track and TAS, and W/V, need to calculate true heading and GS), you need the whizz wheel since the possible multiple choice answers are very close together. Two degrees error in the calculation and you've got the wrong answer.
But if you have one of those "backward" questions (need to calculate the W/V from in-flight data) the possible answers are so far apart that you can just reason yourself to the correct choice, without breaking out the whizz wheel at all. And it's that reasoning they want to test, not a backwards way of using the wheel.
Something along the lines of "you want to travel due North. TAS is 100 knots. You find that you have to steer 353 degrees, and your GS is 89 knots. Calculate the wind velocity.
a. 45/15
b. 135/15
c. 225/15
d. 315/15"
Question like this, don't look at the actual numbers but look at their relation. TAS is 100, GS is 89? Must be a headwind. Scrap answers b and c. Heading is 353 while track is 0? Must be due to a wind from the left. Scrap answer a. So answer d is right.
So the first thing you need to recognise is when NOT to use the whizz wheel.
Young people!
The whizz wheel is a shorthand for the 'velocity of triangles'
Old people!
It's actually a 'triangle of velocities'. You'll get far more results if you google for that.
