People here say that almost 700 for good universities. Over 800 for the top ones. I am not sure, but there are lots of threads where people talk about that. There is a recent one about cut offs.viewtopic.php?f=1&t=3847
May I ask you why your score was so low? You didn't know the content, you made mistakes, you ran out of time? According to what you answer, I should be able to give you some advice. I am a Math tutor. I haven't taken the MGRE yet. Not sure if I ever will because for now I can't afford studying in a university. I am too old (57), and there is no way I will be able to repay it. to get a loan to sudy. I have studied in my country, and that will have to be enough.
But I worked on most of the available problems at some point, and I like working on them because they are a lot of fun. I took the general GRE and I gotm161 in the quantitative part. In the verbal part I didn't do goo, mostly because I am not a native speaker. I got 147. I got the same than you in the writing. Yo me is a success, though! I took it 5 years ago. So, these scores are old, anyway, I also took the TOEFL about 10 years ago, and I did good.
You are going to take it twice. That will give you more experience. But maybe you should consider cancelling (if you still can) the first one to avoid a bad record. I think that you can cancel your scores, though.
Let's see what people over here say,