ACT prep

Our daughter just took the ACT for the first time, and though her score was really good, our umbrella school recommended that she take it again and try to improve her score by 2-4 points as she would be eligible for full scholarship at that level. She wants to improve her score on the math portion, but I’m not sure how to direct her in studying for it. Any suggestions on materials that would help her focus on the math part of the test?

Thanks