I cannot recommend
Target Test Prep enough for improving your score in the quantitative section of the GMAT.
When I took my first practice quantitative section, I had no idea how to approach the problems. I ran out of time and, as a result, my score was very low.
I researched online and found that people had recommended TTP. I had used Khan Academy in high school to improve my SAT score, so I felt like an online, interactive course like TTP would be helpful for me.
I began seriously studying with TTP in December. I had a month of school vacation, so I dedicated around 5 hours a day to going through lessons and doing practice questions. At the beginning of the course, I must admit that I felt it was very tedious, and I wasn't sure if it would really be helpful. I took another practice math section a couple weeks into my TTP studying, and my score did not improve -- I felt very discouraged and almost decided to quit the course. But I decided to keep going for a few more weeks. The further into the course I went, I began to enjoy it more and more, and I also recognized seeing the types of problems/topics I was learning on my practice tests.
I finally finished the course at the end of January. My practice test scores improved by a large amount, but I still needed more practice. I also noticed that I needed to go back and review the early concepts in TTP, like number properties. These early chapters felt very tedious and boring at the time, and I was skeptical that all the details and shortcuts would come in handy. But after going through the whole course and taking a few practice tests, I realized that every single lesson in TTP is there for a reason, and these foundational concepts and shortcuts were extremely helpful.
I continued to use TTP until March as I took practice tests and reviewed the concepts I had difficulty with. The few days before my official GMAT exam, I went back through the course took notes of the important lessons and strategies from all of the chapters.
Ultimately, after a few months of using TTP, I ended up getting a 705 on the GMAT Focus (99th percentile).
TTP's math prep was incredibly thorough and helped me become familiar with the different topics and types of questions on the GMAT. The structure of the course helped me reinforce the concepts after learning them. It gives easy, medium, and hard quizzes after each topic as well as review quizzes that cover a few topics at a time. It also helped me with test taking strategies and time management. Again, keep in mind that the course is thorough and long. But if you have the willpower to get through it, you will be amazed. You really just have to trust the platform because it is so comprehensive and really prepares you well. Even if it might seem like it in the beginning, there is no busy work, and every lesson you learn is directly applicable to questions you will see on the actual test.