I'm not going to tell you how long ago I took my master's test, but they let us use an abacus
Virgil's advice is good, but keep in mind that your test is being administered by the West Virginia Fire Marshall. Unless things have changed quite a bit, I don't think they are qualified. You might want to find out about "exceptions" (in the NEC) because to a fireman, always is always and never is never. The previous fire marshall (thank goodness he is no longer in charge) used to feel that exceptions shouldn't be allowed since they were too confusing. Well, they can be, but he's a fireman & should be confused.
Anyhow, I guess you can tell I don't think much of our licensing setup.
Since you know how to read, you're halfway there, be familiar with the calculation examples in the back of the code book and know how to use the index (that is very important since you can spend a lot of time trying to find something). Be sure to read each question in its entirety, don't jump to conclusions.