The SHL online practice numerical reasoning is, thankfully, not what you will sit. As I said above you are better off practicing your basic skills and improving speed and accuracy. All of the questions, with the exception of the 'calculate the area' questions, are maths wrapped up in a sentence. It may seem a little weird but some of the 11+ maths test papers are closer to what you will receive, all be it without the multi choice element. Type 11+ maths test papers into google or have a look at
Sample Standard Short Tests - AE Tuition . Section 4 of Harry Trolley/Ken Thomas How to Pass Numeracy Tests is also spot on for what you will get.
With practice there is no reason you can't finish the paper or at least get close. The maths element of the day is probably the least scary as, no matter how you wrap it up, it is basic maths and not subject to personal interpretation as the verbal reasoning can be.
Mental rehearsal for the capacity test could be useful too. When following the flight director bars the controls are reversed. Anyone who is used to flying a flight director, with out a bit of thought, will come a croper when the pressure gets ramped up towards the end and the bars are going all over the place. As you get more and more to look for and listen to it is easy to revert back to what you have been used to over the past x amount of years of FD flying, which can screw you up if the bar moves left and you automatically move left with it making the situation worse!
Best of Luck