In reality it depends how good you are, and how you visualise maths problems. Comparing it to other subjects is really apples and oranges. I did Maths, Further Maths, Product Design and AS in Physics and Art. Sure Maths is remembering formulas, but when I did Product Design I had to learn 10+ diagrams of manufacturing techniques.
Most formulas are given to you in the cores (c1-c4), S1 has all relevant formula. M1 has NO formulas given (have to remember 5-6 suvat equations) and D1 gives no formulas (you have to remember all the algorithms).
Edit: Edexcel btw