Successful Strategy Consulting does not require you to be a mathematician but a comfort with figures and good mental arithmetic is essential. Credo, like most consultancies, has a numerical test and will also test numeracy during case studies.
This is likely to focus on some key skills:
If you haven’t used your maths in a long time, practice basic sums – in your head and on paper.
Practice rounding figures up and simplifying calculations – speed and approximate figures can be a better idea than a time consuming accurately worked long division.
Make sure your workings are clear and take your time with calculations that can’t be done in your head.