As the others have indicated, there are things you can do about this. Being accurate is just another part of the GMAT skill set. So just as you have learned about other aspects of scoring high, you can learn how to be more accurate.
For one thing, we are all creatures who adapt to our environments. So if you get smoked enough times by not answering the question asked, for instance, after a while you will start making sure that you are answering the right question.
Also, you can start catching yourself in the act. For instance, if you have a tendency to make crazy little addition mistakes, once you become aware of your pattern, you can catch yourself, "Hey wait, I almost added 26 and 26 and got 56."
One thing that people do is to get excited at certain times, such as when they have just done a bunch of complex stuff and are close to answering a question. So excited to have completed the hard parts, they jump to the wrong answers. So there's one thing you can watch out for.
Also, when practicing, remember that getting a concept does not constitute getting a question right. That's a distinction that can be easily glossed over. People think like, "Well I got the idea." So when you are doing practice questions take into account not only level of understanding but also accuracy, and notice whether you had to recalculate because you made a silly mistake initially.
Finally, another approach you can use to achieve greater accuracy is to become more self aware. For example, in my case, I used meditation to become aware that some childish aspect of me actually liked to, and still to a degree likes to, make silly errors. So I was actually making them intentionally. I discussed what I did about that in this post.
https://www.beatthegmat.com/rocked-the-g ... 82365.html
I also discuss a meditation approach I used in this post. The blog post is health oriented, but the approach works for achieving anything.
https://healingchronicles.com/2014/01/06 ... n-to-heal/
