Hi demo1,
I’m glad you reached out, and I’m happy to help. Improving from 350 to 650 is a significant task, so you may need more than just three months to achieve your score goal. Thus, I recommend that you track your progress over the next few months, and if you are not improving at the pace you need, then consider scheduling your exam for a later date. You can read more about this in my article about
how long to study for the GMAT.
Since you self-admittedly have weak GMAT quant skills, you will need to follow a linear study plan that allows you to slowly build GMAT mastery of one topic prior to moving on to the next. Within each topic, begin with the foundations and progress toward more advanced concepts. For example, if you are learning about Number Properties, you should develop as much conceptual knowledge about Number Properties as possible. In other words, your goal will be to completely understand properties of factorials, perfect squares, quadratic patterns, LCM, GCF, units digit patterns, divisibility, and remainders, to name a few concepts. After carefully reviewing the conceptual underpinnings of how to answer Number Properties questions, practice by answering 50 or more questions just from Number Properties. When you do dozens of questions of the same type one after the other, you learn just what it takes to get questions of that type correct consistently. If you aren't getting close to 90 percent of questions of a certain type correct, go back and seek to better understand how that type of question works, and then do more questions of that type until you get to around at least 90 percent accuracy in your training. If you get 100 percent of some sets correct, even better. Number Properties is just one example; follow this process for all quant topics.
When you are working on learning to answer questions of a particular type, start off taking your time, and then seek to speed up as you get more comfortable answering questions of that type. As you do such practice, do a thorough analysis of each question that you don't get right. If you got a remainder question wrong, ask yourself why. Did you make a careless mistake? Did you not properly apply the remainder formula? Was there a concept you did not understand in the question? By carefully analyzing your mistakes, you will be able to efficiently fix your weaknesses and in turn improve your GMAT quant skills.
Each time you strengthen your understanding of a topic and your skill in answering questions of a particular type, you increase your odds of hitting your score goal. You know that there are types of questions that you are happy to see and types that you would rather not see, and types of questions that you take a long time to answer correctly. Learn to more effectively answer the types of questions that you would rather not see, and make them into your favorite types. Learn to correctly answer in two minutes or less questions that you currently take five minutes to answer. By finding, say, a dozen weaker quant areas and turning them into strong areas, you will make great progress toward hitting your quant score goal. If a dozen areas turn out not to be enough, strengthen some more areas.
So, work on accuracy and generally finding correct answers, work on specific weaker areas one by one to make them strong areas, and when you take a practice GMAT or the real thing, take all the time per question available to do your absolute best to get right answers consistently. The GMAT is essentially a game of seeing how many right answers you can get in the time allotted. Approach the test with that conception in mind, and focus intently on the question in front of you with one goal in mind: getting a CORRECT answer.
In order to follow the path described above, you may need some new verbal and quant materials, so take a look at the GMAT Club reviews for the
best quant and
verbal courses.
You also may find my article with more information regarding
how to score a 700+ on the GMAT helpful.
Feel free to reach out with any further questions.
Good luck!