Hey! I do English Literature for A2 and somehow failed the literacy one, which caused me much confusion. After doing some practises online, i was still failing... turns out i had been pressing 'next' on the grammar section (where you add in the punctuation and what not)... good job there is no test for common sense or i would have failed every time.
The only advise i can give for this it to know the structure of the test by doing as many prices one's as you can, so you know exactly what you are doing and don't miss out anything important.
As for the maths, again, the practise's helped me to stimulate my brain slightly after not doing maths for so long, however they give you a piece of paper to scribble things down on- USE THIS! I'm not even joking, without this, i would have failed.
Also, although you may want to go through and double check your answers, I found on a few occasions i had written my answer in the box and went to check my sum over again, only for the question to end and move onto the next one, so my answer was' submitted and it went down as unanswered. The time taken to double check cost me the question, so always submit your answer before double-checking to make sure you answer at least every question.
Hope this helps. Good Luck!