If you can remember formulas then it will save you a lot of time in test situations. You won’t have to go to your bound/summary/cheat book to find them because you’ll already know them.
So how do you remember formulas?
One of the best ways of remembering a Maths formula is to write it down every time you use it. For example write A = L x W each time you are working out the area of a rectangle.
By writing down a formula every time you use it you’ll find that in a short time you’ll easily remember it.
When it comes to exam time do the same thing. Write down the formula as you use it and make sure it’s in your “Bound Book” that you take into the exams.
This “writing the formula” method was the way I learnt Maths formulas when I was at school – we had to remember them then because we weren’t allowed to take anything into exams except something to write with and our calculators (non-programmable).
I teach my students to remember formulas this way and it works for them. If you practice it you’ll find that it can work for you too.