i never did CrackMath, but if you own Math Destroyer, DEFINITELY do a couple tests. I'm a math minor so i'm not terrible at math, and i thought topscore and kaplan and all those were easy. but when i got to math destroyer, i struggled with time (i ended up struggling with time on the real QR section).. so def practice math destroyer. some of the questions i got on the real section were VERYYY similar to ones i did in math destroyer. at least for my test, 75% of the questions were word problems.. which destroyer prepares you for. good luck