Hi ,
Look at my other post for Math Needs :
number-properties-approach-120562.htmlSince you say , you are done with
Mgmat math guides more than once, I would recommend go grab total gmat math by Jeff Sackmann. It has solid concepts plus good GMAT Like practice and challenge problems along with explanations. Once done grab
Mgmat Math QB ( 5$ each X 5 ) and finish them off. Come back to OG 12 and do practice it all over again. Since your concepts are good ( if at all after using this approach !) , Dedicate a week to OG 12 Math and use an
error log to review the problems you got wrong or felt tough the previous day. Re do them again the next day and start with that day's practice. I used total Gmat Book and should say its an awesome book. Take a gmat prep test and if you are on q -44 , use
gmat club tests ( at-least 12 of them to boost your Math skills to 48plus )

Hoogly