I have already served in the military years ago. But I wondered if there was a primer that might have helped me improve my test scores. I think this book would help. Unfortunately it's hard to learn enough from a book to do well on the math and reading comprehension of the ASBAB test. Study hard in math and English class in high school. It's hard to cram from a book to pass a comprehensive test that covers many topics. I think it may give you a few extra points, however.
In the 1950s, the military adopted a single exam known as the Armed Forces Qualification Test (AFQT). Used as a screening tool, the AFQT measured a recruit’s ability to absorb military training and their future potential. It was supplemented by service-specific battery tests for the purposes of MOS classification. In 1972, the Department of Defense determined that all services should use one exam for screening and assigning individuals to an MOS. The AFQT was phased out over a two-year period in favor of the current Armed Services Vocational Aptitude Battery (ASVAB) test.
The P&P-ASVAB gives you a set number of questions to answer and a set time limit. If you finish a section before your time runs out, you may go back and review your answers and change them if you want to. It’s better to answer all of the questions on the P&P-ASVAB – there is no penalty for guessing because only correct answers are added to make up your final score.
Our ASVAB practice test questions are categorized to help you focus your study. Just like in the real exam, each of our questions will have four possible answers to choose from. The questions are similar to what you can expect on the actual ASVAB exam. After you submit answers to the practice questions, a test score will be presented. In addition, you will be given rationales (explanations) to all of the questions to help you understand any questions you may have gotten wrong.

The Armed Forces Qualification Test (AFQT) is used by all of the Services to determine if an applicant is eligible for the military. Four of the ASVAB subtests are combined to form the AFQT. It measures general cognitive ability and is composed of verbal and mathematics subtests. AFQT scores are grouped into categories for reporting purposes. The table below shows the AFQT categories and the percentile score ranges corresponding to the categories. Applicants that score in AFQT category IIIA or higher may qualify for enlistment incentives.