Back to the theory....
I passed my Grade 6 in April, so I hope to help you out here

It isn't too bad at all.
These are the TOP 3 Figured bass chords in Grade 6 theory:
*5/3 chord
*6/3 (6) chord = 1st inversion
*6/4 chord = 2nd inversion
1)The number below the given note on the stave, is asking you to effectively to COUNT UP from the given note.
2)You always start from the bottom number: eg 6/3... (usually written as 6). So, you would count 3 NOTES ABOVE the given note on the stave, to give you the second note in the chord.
3)Then you count 6 up, from the GIVEN NOTE which is on the stave.
........ and there shall be your chord..........
On the other topic, I would like to make a point in saying, that all because a particular person has degree/diploma/grades underneath their belt, that alone does not make that somebody a good teacher. It shows that the person has knowledge and an understanding of the subject, but if the teaching standards are poor, then the degrees are worthless in themselves. Plus, all because someone hasn't got the highest qualification going, it therefore does not mean that someone is not knowledgeable either. I'm pretty sure we can all learn from each other here. Even the most well educated ones amoung us, would more than likely agree with me when I say that you never stop learning in music. Listening to others and therefore learning from others, is music in my eyes.