To improve in math, I suggest a systematic approach, in which you take the time to master each topic/concept (e.g., percents, ratios, geometry, etc).

So, for each topic/concept, you should:
1) Learn the underlying concepts (rules, attributes, notation, etc.)
2) Learn GMAT-specific strategies related to that topic
3) Practice dozens of questions all related to that one topic.
4) Don't stop working on that topic until you have mastered it
Then, and only then, move on to the next topic.

As you practice, it's important that you identify and strengthen your weak areas. One way to do this is to use an Error Log (aka Improvement Chart) while completing questions from the Official Guide (OG). You can find a free downloadable Improvement Chart here: https://www.beatthegmat.com/mba/gmat-error-log

I also suggest that you spend a lot of time reviewing the responses from the Experts on this site, since they often model the steps you should be taking when answering question.

In addition to learning the core concepts and GMAT-specific strategies, be sure to work on your endurance and test-taking skills (e.g., time management) by taking several practice tests.

If you're interested, we have a free GMAT time management video at https://www.gmatprepnow.com/module/gener ... es?id=1244

Cheers,
Brent