If you are good in math can you give me some advice?

I don't study. (if you have a graphing calculator, you can cheat and put the stuff in the calculator before hand)
*I am not endorsing cheating

practice makes you perfect
especially always in proctice before exams many times
my marks is pretty well about 94%

Math is kinda like playing the piano.  Practice makes perfect.  My son is in the 5th grade and I make up little exams for him.  Just the basics - addition, subtraction, multiplication, division, fractions, finding percentage, etc.  At least once a day I will add a column of random three and four digit numbers, then get the average, just for fun and to keep me sharp.

Study, learn by reverse checking answers already given.  Practice.

Um, any specific problem?

generally get a calculator (hell adding up huge sums!) if you are planning to do really advanced maths you'll need a graphical calculator whereas otherwise a simple scientific one will do.

Umm make sure you know your units well and how to convert them eg millimetres, centimetres etc and the same applies for fractions/decimals/percentages -  the earlier you get the hang of them and how to change them - the easier it will be.

Oh and if you get stuck on a problem, look at the answer and try to work out how that solution is reached - study in reverse like the other poster said.

If you get stuck ask for help!

And no, there's nothing 'special' really to do before you study maths - except maybe getting in the right frame of mind - there are warm up activities you can do to wake up your brain.

the perfect tips is too keep on practise maths questions... and another tips is that if you do not understand the question go and ask a tutor or a teacher or a person that knows the question to teach you...

Do lots and lots of example questions (to which you have the answer and preferably a worked solution). Once you can do these easily, move onto harder ones, rinse, and repeat.

It is better in the long term if you don't memerise 'tricks' or rote learn how do do specific problems. If you can understand what is actually being asked of you, it is usually easier to figure out what you have to do, rather than just treating them as 'numbers'.

just make sure you understand the concepts, like why a formula works, instead of just trying to memorize it

No matter how difficult it seems, its only a combination of adding, subtracting, multiplying and dividing. You know it already so don't be intimidated.

As everyone else is saying, practice is really important to being good at math. But there is something else that is very important to developing your mathematical ability: self-confidence. See, math is hard. Sometimes you need to think about something for a long time before it makes sense (days and weeks, even). Many people give up too early when they don't understand something. They think: "I couldn't understand it right away, I must be bad at math."

Guess what, movies and books usually get it wrong. You don't need to be a genius to be good at math. You just need to be stubborn. Don't stop working until you can solve the problem.