Mathematics is one subject that can make a big difference to the marks you notch up at the IIT-JEE. Predictably, it is one subject that requires a great share of your time and attention.

It requires a lot of written practice, in geometry and integral calculus, and intuitive guesswork. You can develop a knack for intuitive guesswork only if you attempt as many problems you can.

The Mathematics texts published by Tata McGraw Hill, Arihant and Hall-Knight (for algebra) are what I'd recommend. S. L. Loney's books are regarded as the best, but their questions are at a level that's higher than the IIT-JEE nevertheless, read them hone your understanding co-ordinate geometry. Arihant's books contain many solved problems and a number of tricks that will help you save a lot of time. Prepare notes on the important concepts/ formulae and revise them frequently. I would rate complex numbers as a tough topic but it is equally rewarding because it can be used in geometry. Co-ordinate geometry carries a lot of weight and requires a lot of patience because of the vastness of the concepts involved in the topic.

Inside the examination hall, look for hidden answers in the questions. Many integrals, for instance, turn out to be zero and this can be deduced by looking at the function, without wasting time in solving the problem completely. Permutations and combinations and probability are usually found in matrix matches and comprehension, and can be cracked with a bit of intelligent guessing, looking at the values involved and the numeratordenominator in the options. Using these tricks of the trade is better than spending a lot of time on one question. Math is written practice + tricks + intelligent guessing.