On the Learning Tools website, your options include 10-question ASVAB General Science practice tests. These ask you to use terms in context, define terms, and complete basic math problems. You may also be asked to categorize items and answer questions related to general scientific facts. The ASVAB Math Practice Tests are exercises that challenge your ability to correctly answer word problems based on sales and profit, speed, time, area, and other relational concepts.
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).