Questions in the Quantitative Reasoning measure of the GRE® General Test ask you to model and solve problems using quantitative, or mathematical, methods. Generally, there are three basic steps in solving a mathematics problem:
- Step 1: Understand the problem
- Step 2: Carry out a strategy for solving the problem
- Step 3: Check your answer
Here is a description of the three steps, followed by a list of useful strategies for solving mathematics problems.
Step 1: Understand the Problem
The first step is to read the statement of the problem carefully to make sure you understand the information given and the problem you are being asked to solve.
Some information may describe certain quantities. Quantitative information may be given in words or mathematical expressions, or a combination of both. Also, in some problems you may need to read and understand quantitative information in data presentations, geometric figures or coordinate systems. Other information may take the form of formulas, definitions or conditions that must be satisfied by the quantities. For example, the conditions may be equations or inequalities, or may be words that can be translated into equations or inequalities.
In addition to understanding the information you are given, it is important to understand what you need to accomplish in order to solve the problem. For example, what unknown quantities must be found? In what form must they be expressed?
Step 2: Carry Out a Strategy for Solving the Problem
Solving a mathematics problem requires more than understanding a description of the problem, that is, more than understanding the quantities, the data, the conditions, the unknowns and all other mathematical facts related to the problem. It requires determining what mathematical facts to use and when and how to use those facts to develop a solution to the problem. It requires a strategy.
Mathematics problems are solved by using a wide variety of strategies. Also, there may be different ways to solve a given problem. Therefore, you should develop a repertoire of problem-solving strategies, as well as a sense of which strategies are likely to work best in solving particular problems. Attempting to solve a problem without a strategy may lead to a lot of work without producing a correct solution.
After you determine a strategy, you must carry it out. If you get stuck, check your work to see if you made an error in your solution. It is important to have a flexible, open mind-set. If you check your solution and cannot find an error or if your solution strategy is simply not working, look for a different strategy.
Step 3: Check Your Answer
When you arrive at an answer, you should check that it is reasonable and computationally correct.
- Have you answered the question that was asked?
- Is your answer reasonable in the context of the question? Checking that an answer is reasonable can be as simple as recalling a basic mathematical fact and checking whether your answer is consistent with that fact. For example, the probability of an event must be between 0 and 1, inclusive, and the area of a geometric figure must be positive. In other cases, you can use estimation to check that your answer is reasonable. For example, if your solution involves adding three numbers, each of which is between 100 and 200, estimating the sum tells you that the sum must be between 300 and 600.
- Did you make a computational mistake in arriving at your answer? A key-entry error using the calculator? You can check for errors in each step in your solution. Or you may be able to check directly that your solution is correct. For example, if you solved the equation for x and got the answer you can check your answer by substituting into the equation to see that .
There are no set rules — applicable to all mathematics problems — to determine the best strategy. The ability to determine a strategy that will work grows as you solve more and more problems. What follows are brief descriptions of useful strategies. Along with each strategy, one or two sample questions that you can answer with the help of the strategy are given. These strategies do not form a complete list, and, aside from grouping the first four strategies together, they are not presented in any particular order.
The first four strategies are translation strategies, where one representation of a mathematics problem is translated into another.
- Strategy 1: Translate from Words to an Arithmetic or Algebraic Representation
- Strategy 2: Translate from Words to a Figure or Diagram
- Strategy 3: Translate from an Algebraic to a Graphical Representation
- Strategy 4: Translate from a Figure to an Arithmetic or Algebraic Representation
- Strategy 5: Simplify an Arithmetic or Algebraic Representation
- Strategy 6: Add to a Geometric Figure
- Strategy 7: Find a Pattern
- Strategy 8: Search for a Mathematical Relationship
- Strategy 9: Estimate
- Strategy 10: Trial and Error
- Strategy 11: Divide into Cases
- Strategy 12: Adapt Solutions to Related Problems
- Strategy 13: Determine Whether a Conclusion Follows from the Information Given
- Strategy 14: Determine What Additional Information is Sufficient to Solve a Problem