Take a practice test. The ASVAB is broken down into nine individual parts. Each portion tests your knowledge on a specific subject ranging from general science and math to spatial orientation and mechanics. Practice tests can be found online or are frequently included in study guides, which can be purchased at your local bookstore or checked out from the public library. Use a timer, and adhere to the given time limits for each section of the test. Keep in mind that certain portions of the ASVAB are designed to not be finished.
Learn to interpret the results so you can understand your score. The ASVAB has several scores assigned to it. The most important is known as the AFTQ, and it is used to determine your eligibility for military service. Only four of the nine test subjects are used to compute the AFTQ---vocabulary, reading comprehension, arithmetic reasoning and mathematical skill. If your score in any of these areas is low, you will want to take steps to remedy the situation immediately. A low AFTQ can render you ineligible for service.
Study, study, study. Make flash cards to improve your vocabulary by writing the word on one side of an index card and the definition on the other. Flash cards can also be used to improve your arithmetic skills. Solving basic math problems in your head can help reduce the amount of time needed to finish the exam. By working out simple story problems on a whiteboard, you will be able to see any mistakes.
Determine which of the non-AFTQ areas are used to determine your eligibility for specific careers. If you have a certain job in mind, you may need to do well in several of the other subtests in order to qualify for it. If so, be sure to practice testing in these subjects also.
Ask which format your test will be given in, and take another practice exam that mimics your probable testing conditions as closely as possible. The ASVAB is given in both pencil-and-paper and computerized versions.