I took the ASTB within the last two months, I agree, no calc on the ASTB. I studied quite a bit and still didn't complete the math portion of the test. I'd say in preparation give it a good effort, however at some point you aren't likely to greatly improve with continued practice on the math. For the most part, you're a math wiz, or you're not. I did the whole Honors/advanced math thing in High school, however only Calc. one for a business degree in college.
A word of advice when taking the test, instead of flagging questions you don't know and moving on, mark your best guess and flag the question. It came down to the wire for me, and with the computer/server lag and 45 seconds to go, I wasn't able to fill in the blanks as I would have on a paper test and ended up leaving several of the math questions blank. All in all I did alright, pulled a 60. I definitely owe a bit of that score to the search feature, and all the knowledgeable folks on AirWarriors. The Arco book was helpful as well. I spent plenty of time reading past threads. A definite thanks goes out to all the guys/gals who are sincerely willing to share their knowledge and time to help the "wanna-Bs." Thanks.