I feel this course will help you, I too failed by 4 marks once and then 3 after before finding this, and it helped strengthen my weaker areas. But in terms of revising the main thing is learning the times tables mainly 7s and 12 also strengthen your fractions. The way I approached revision was by splitting the mental arithmetic into sections: money questions, percentages, fractions to percentages and distances conversion when they give you convert xkm to miles I found it easier to divide by 8 then times 5 for example 24km to miles = 8/24 =3 x 5 = 15, rather then building it up as that wastes time. hope that helps, and I know this is cliche but don't be nervous trust me you'll be fine with enough prep approach the test with confidence and you'll be less likely to panic/ make mistakes during the mental arithmetic. all the best