If you didn't earn a score that was high enough to be accepted to your chosen branch of the military, or if you didn't earn a line score high enough to qualify for a desired career option, then you may retake the ASVAB. You must wait a full month before you can take the ASVAB a second time. If you wish to take the test a third time, you must wait another month from the date of your second attempt. After the third attempt, there is a waiting period of 6 months before you can take the test again.
My recruiter told me about this book so I ordered it and got it 3 days later from the Military Bookstore. I got this book and it is awesome. The cd works great and every thing I needed and more to help me was in there. I recommend this book to everyone who is thinking of going in the service and wants to get a real job! GET THIS BOOK AND SCORE HIGH!!!!”

You can't use the AR and MK score shown on your ASVAB Score Sheet. The Score Sheet shows "number correct" for your AR and MK Scores, because "number correct" is what is used for job qualifications. However, the military does not use this same score when computing the AFQT. They use the "weighted scores" of the ASVAB sub-tests for AR and MK. Harder questions in these areas get more points than easier questions. The "weighted scores" for AR and WK are not listed on the ASVAB score sheet given to you after the test.
The test measures competency in 9 different subjects, which include General Science, Electronics Information, Auto and Shop Information, Mechanical Comprehension, Assembling Objects, Word Knowledge, Paragraph Comprehension, Arithmetic Reasoning, and Mathematics Knowledge. These last four sections- Word Knowledge, Paragraph Comprehension, Arithmetic Reasoning, and Mathematics Knowledge are the most important, as they make up something called the AFQT (Armed Forces Qualifications Test). An applicant’s AFQT score is what determines whether or not they are able to serve in the military at all, as each branch has minimum scores for enlistment.
After a candidate has completed the ASVAB they must wait one calendar month before retaking the exam. An additional calendar month must pass before retesting a second time. Six calendar months must pass before retaking the test a third time. The scores received from the ASVAB may be used for enlistment for up to two years from the initial test date. 
Examinees also receive a score on what is called the Armed Forces Qualification Test (AFQT). AFQT scores are computed using the Standard Scores from four ASVAB subtests: Arithmetic Reasoning (AR), Mathematics Knowledge (MK), Paragraph Comprehension (PC), and Word Knowledge (WK). AFQT scores are reported as percentiles between 1-99. An AFQT percentile score indicates the percentage of examinees in a reference group that scored at or below that particular score. For current AFQT scores, the reference group is a sample of 18 to 23 year old youth who took the ASVAB as part of a national norming study conducted in 1997. Thus, an AFQT score of 90 indicates that the examinee scored as well as or better than 90% of the nationally-representative sample of 18 to 23 year old youth. An AFQT score of 50 indicates that the examinee scored as well as or better than 50% of the nationally-representative sample.
My daughter bought this book to study for her ASVAB test. She took it the first time and did not get the score she needed. So she got this book to help her study and to raise her score. She took her test again and her score raised 14 points. I recommend this book to those that need help studying or need a higher score. The book has a lot of information about the test and has practice questions as well. Overall, the book is very useful for those who want to do well on the ASVAB.
If you are enlisting in the military, good - a patriotic journey, where you can build skills and see the world. However there is one thing your recruiter didn't tell you. Your ability to get into a department that you want, depends on how well you can take a quiz - just like you did with the SAT, or whatever those test are called in current times. Those test asked those really stupid questions about the cost of ice cream if a train leaves New York at 4:00 and it is 20 degrees on Colorado. This book will teach you how to answer those ridiculous questions that WILL control your destiny. Get a copy and memorize it... then serving your country will lead to a great career.
After the final ability estimate is computed, it is converted to a standard score on the ASVAB score scale that has been statistically linked to the ability estimate through a process called equating. Equating studies are conducted for every paper and pencil ASVAB form to ensure that scores have the same meaning regardless of which test form the examinee receives.
You can take the test as a junior or senior in high school and use the score to enlist, provided that you are at least 17 years old and took the test no earlier than 2 years before you begin enlistment processing. If you are at least 17, you can take the test at a Military Processing Station (MEP) or a satellite Military Entrance Test (MET) location.
A century or so later, in the hands of writers such as Jean Froissart, Miguel Cervantes and William Shakespeare, the fictional knight Tirant lo Blanch, and the real-life condottieri John Hawkwood would be juxtaposed against the fantastical Don Quixote, and the carousing Sir John Falstaff. In just one play, Henry V, Shakespeare provides a whole range of military characters, from cool-headed and clear-sighted generals, to captains, and common soldiery.
The ASVAB is a series of timed aptitude tests that are used to classify selected candidates into appropriate job roles as well as ultimately decide the eligibility of candidates for US military service.  In other words, perform poorly on this test and you could severely limit your opportunities in the military or even prevent yourself from serving.
Command over the U.S. Armed Forces is established in the Constitution. The sole power of command is vested in the President by Article II as Commander-in-Chief. The Constitution presumes the existence of "executive Departments" headed by "principal officers", whose appointment mechanism is provided for in the Appointments Clause. This allowance in the Constitution formed the basis for creation of the Department of Defense in 1947 by the National Security Act. The DoD is headed by the Secretary of Defense, who is a civilian and member of the Cabinet. The Defense Secretary is second in the U.S. Armed Forces chain of command, with the exception of the Coast Guard, which is under the Secretary of Homeland Security, and is just below the President and serves as the principal assistant to the President in all defense-related matters.[16] Together, the President and the Secretary of Defense comprise the National Command Authority, which by law is the ultimate lawful source of military orders.[17]
The IRT model underlying ASVAB scoring is the three-parameter logistic (3PL) model. The 3PL model represents the probability that an examinee at a given level of ability will respond correctly to an individual item with given characteristics. Specifically, the item characteristics represented in the 3PL model are difficulty, discrimination (i.e., how well the item discriminates among examinees of differing levels of ability), and guessing (i.e., the likelihood that a very low ability examinee would respond correctly simply by guessing).
Division of Military and Naval Affairs (DMNA) Recruitment Incentive and Retention Program (RIRP). RIRP is a New York State program that offers tuition assistance for members of State military forces, such as the Army and Air National Guard and the Naval Militia. New York also offers a Veterans TAP Grant, which is received in addition to the regular TAP Grant.
The ASVAB test can be taken at your school or a MEPS (Military Entrance Processing Stations) or MET (Mobile Examination Test) sites.  When the ASVAB is administered at your school, it is usually part of the Student Testing Program or Career Exploration Program.  When the ASVAB is given at MEPS or MET sites, it is part of the Enlistment Testing Program.  The ASVAB test content is the same no matter where you take it, except that you will not have to take the Assembling Objects test if you take the test at your school (as part of the Student Testing Program).  When you take the test in the Student Testing Program you will receive three composite scores (Verbal Skills, Math Skills, and Science and Technical Skills).  When you take the ASVAB as part of the Enlistment Testing Program, you will receive an AFQT (Armed Forces Qualification Test) score and Service composite scores.  These scores are used for assigning your military job.
International protocols restrict the use, or have even created international bans on weapons, notably weapons of mass destruction (WMD). International conventions define what constitutes a war crime, and provides for war crimes prosecution. Individual countries also have elaborate codes of military justice, an example being the United States' Uniform Code of Military Justice that can lead to court martial for military personnel found guilty of war crimes.
After adding so much information to the aptitude test, there was a bit of difficulty interpreting the test results. In addition to that, a vast majority of test takers were deemed as being under qualified based on their test results. This is why the percentile change was made. It ensured that a 50% actually correlated with a person doing better than 50% of the test takers. Those revisions have worked hand-in-hand with the preparation of the armed forces.