For many people this section seems to be the most terrible, especially if you were not engaged for a long time in mathematics. But actually problems there are not especially difficult, at level of middle classes of school. There  will be tasks on arithmetics, algebra and geometry, there will be no trigonometry and all such. But also there will be no calculators, therefore train to solve tasks in mind, and repeat key rules.

Which rules do you need to repeat? Basically, you need to be able to do the following without the calculator:

    * to add, subtract, multiply and divide figures (negative too)
    * to add, subtract, multiply and divide fractions
    * to transfer fractions in decimal and back
    * to solve the algebraic equation
    * to find percent
    * to find an average
    * to calculate the areas of rectangles, triangles and circles
    * to know the basic terminology and definitions, for example, integrals, etc.

Questions consist of the decision of tasks (approximately two thirds of questions) and sufficiency of data. The second type of questions appears only in GMAT, therefore the majority of people with it are unfamiliar. They consist of a question and two data. You do not need to answer; your problem is to define, which of data gives enough information for the answer to a question. You will be given the instruction on the answer to these questions, and all questions will have identical variants of answers, i.e. you will need to tell, whether it is possible to answer this question by means of one data, or both, or any.

Together with the general result you will receive also separate result on computing section, on a scale from 0 to 60, reflecting your result in comparison with others handed over GMAT. The average score in this section is 35.