Personally I think that the requirement to commit all the various performance factors to memory for the exam sets a very dangerous example.
In the 'real' aeroplane world, you NEVER attempt to remember all the performance degrades for contaminated runway operations - and short, wet grass is indeed a contaminated runway, for example.
I feel that exam students should be permitted to have access to Safety Sense Leaflet 7 for this exam - it shouldn't be a memory test!
You can also use an electronic calculator for this exam, provided that it doesn't have any 'navigation' functions included.