does mcgraw hill have decent practice tests? & calculator tips for ACT??

I just started practicing for the ACT, and im trying to find good practice materials. I was using the Mcgraw Hill ACT practice plus (http://www.mhpracticeplus.com/act.php) and i did surprisingly well on it which somewhat concerns me… does anyone know if the material is any good? if not what are some other online ACT prep tests i can use? i tried using the one directly from the ACT website but its extremely annoying bc i have to keep scrolling up and down. also im wondering does anyone have any tips for using the calculator on the ACT?? i am terrible at math and i need to atleast get an 18 on the sat to get into the college i want!! thanks

I don’t like McGraw Hill at all… I find it to be much easier than the real test. Princeton Review is a better option, but official tests are really what you should focus on.

McGraw Hill practice test is the worse. A lot of mistakes in Math.