Many students have trouble finishing the math section on the GMAT within the given time constraints. Here are some tips to help you finish the math section on time!
(1) If you're like most students, you probably tend to rush when you read a question for the first time. Then, thirty seconds later you look back at the question only to realize that you have been answering the wrong question or that you didn’t take all of the information into account. When you first look at a question read it carefully, remember or write down all the important information given, and then construct a plan of attack.
(2) While you need to know the basics, this is not exactly a Math or English test. What the GMAT tests is your ability to rapidly apply basic mathematical concepts in creative ways. Remember, these questions were made to be solved in less than two minutes if done in the right manner. There are usually two or three ways to do a math question, but one of the ways is almost always much faster. The best test takers use logic to get around doing complicated calculations as often as possible.
(3) In order to figure out the fastest way to do a problem you should go over the work that you’ve already done to see if there was a better way to solve the problem. Thus, don’t throw away the practice that you’ve already done! Keep the paper that you wrote your practice problems on and pay attention to your mistakes that you made. Not only will this help you find a faster way to do certain questions but it will also help you avoid making the same mistakes again.
(4) Don't start by doing lots of practice problems. At the beginning of your studies you need to focus on strategy first. Once you have the right strategy in mind, then you need to practice. And then review your questions. And then do more practice problems. And then, once you feel comfortable doing each of the questions by section, you should mix the questions up. For example, you should study the fraction section, then the percents section, and so on. Once you've done all of the sections individually, you should then mix up the questions from all of the sections.