Test scores provide only one measure of your skills and abilities.  Test scores and grades, combined with information about your interests, values, skills, and achievements may help you select appropriate occupations for career exploration.  As you explore careers, you can compare your skills with the skill requirements of occupations in which you are interested.
As the speed of technological advances accelerated in civilian applications, so too warfare became more industralised. The newly invented machine gun and repeating rifle redefined firepower on the battlefield, and, in part, explains the high casualty rates of the American Civil War. The next breakthrough was the conversion of artillery parks from the muzzle loading guns, to the quicker loading breech loading guns with recoiling barrel that allowed quicker aimed fire and use of a shield. The widespread introduction of low smoke (smokeless) propellant powders since the 1880s also allowed for a great improvement of artillery ranges.

After World War II, with the onset of the Cold War, the constant technological development of new weapons was institutionalised, as participants engaged in a constant 'arms race' in capability development. This constant state of weapons development continues into the present, and remains a constant drain on national resources, which some[who?] blame on the military-industrial complex.

The General Science section of the test covers earth, space, and physical and life sciences. Because science is such a vast and dynamic topic, focus your study on basic principles. This gives you a good foundation to work through any question that is asked of you. Typical questions may include: “Why is air less dense than water?” or “How do you convert Celsius temperature to Fahrenheit?” The CAT-ASVAB test asks 16 questions in 8 minutes, while the pencil-and-paper version asks 25 questions in 11 minutes.

Arithmetic Reasoning tests the ability to solve basic arithmetic problems encountered in everyday life. One-step and multistep word problems require addition, subtraction, multiplication, division and choosing the correct order of operations when more than one step is necessary. The items include operations with whole numbers, operations with rational numbers, ratio and proportion, interest, percentage and measurement. Arithmetic Reasoning is one factor that helps characterize mathematics comprehension, and it also assesses logical thinking.
NEW! - Utilize these flashcards to help you learn and remember the most important terms you will find on your ASVAB Word Knowledge test.  Navigate through the flashcards by clicking next and previous.  You can press Flip to see the definitions.  If you got the definition correct, mark it "correct" - otherwise mark it incorrect.  When you get through all of the flashcards, you will be given the option to review all the cards, or just the ones you marked incorrect. Good luck!
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.

To be admitted to the ASVAB testing room you will need to show a valid id. It is also important to be on time (or early!) since you will be turned away if you show up after the scheduled start time. The ASVAB can be given via computer or pencil and paper.  If you are testing at a MEPS site you will take it on a computer.  The pencil and paper version is given at most MET sites.  The computer version of the test is given as a "computer adaptive test" (CAT) which means that the test will adapt based on the level of the individual test taker (e.g., if you answer many questions correctly, you may be shown fewer questions).
The Armed Services Vocational Aptitude Battery (ASVAB test--also known as the AFQT (Armed Forces Qualification Test). This is the score used by the recruiter to determine a potential recruit’s enlistment eligibility, assign a recruit to a military jobs, and aid students in career exploration. The AFQT is actually a subset of the ASVAB - only with scores of four of the ten test sections calculated.
The Arithmetic Reasoning section of the test measures your ability to solve arithmetic word problems. You may be asked questions such as “If the tire of a car rotates at a constant speed of 552 times in 1 minute, how many times will the tire rotate in half an hour?” Therefore, reviewing common math key words associated with each operation is recommended. For example, if you see the key words “in all,” the problem deals with addition. If the problem asks you to “find the difference,” you are being asked to subtract. If a question asks “how many times” per day or week, you know you are dealing with multiplication. If it asks “how many in each,” you should be thinking about division. The CAT-ASVAB has 16 questions in 39 minutes; the paper-and-pencil version has 30 questions in 36 minutes.

On 3 December 2015, U.S. Defense Secretary Ashton Carter announced that all military combat jobs would become available to women.[40] This gave women access to the roughly 10% of military jobs which were previously closed off due to their combat nature.[41] The decision gave military services until January 2016 to seek exceptions to the rule if they believe that certain jobs, such as machine gunners, should be restricted to men only.[42] These restrictions were due in part to prior studies which stated that mixed gender units are less capable in combat.[43] Physical requirements for all jobs remained unchanged, though.[43] Many women believe this will allow for them to improve their positions in the military, since most high-ranking officers start in combat positions. Since women are now available to work in any position in the military, female entry into the draft has been proposed.[44]

Again, the ASVAB is a wide-ranging exam covering many different areas. The designers of ASVAB practice tests, at least the high quality ones, know this and have spent time researching past tests to come up with practice tests that feature questions covering areas commonly tested for on the real exam. Thus, taking practice tests is a great way to focus on the material that matters most and avoid wasting your time studying content that likely won’t be on the test.
Capability development, which is often referred to as the military 'strength', is arguably one of the most complex activities known to humanity; because it requires determining: strategic, operational, and tactical capability requirements to counter the identified threats; strategic, operational, and tactical doctrines by which the acquired capabilities will be used; identifying concepts, methods, and systems involved in executing the doctrines; creating design specifications for the manufacturers who would produce these in adequate quantity and quality for their use in combat; purchase the concepts, methods, and systems; create a forces structure that would use the concepts, methods, and systems most effectively and efficiently; integrate these concepts, methods, and systems into the force structure by providing military education, training, and practice that preferably resembles combat environment of intended use; create military logistics systems to allow continued and uninterrupted performance of military organisations under combat conditions, including provision of health services to the personnel, and maintenance for the equipment; the services to assist recovery of wounded personnel, and repair of damaged equipment; and finally, post-conflict demobilisation, and disposal of war stocks surplus to peacetime requirements.