Hi Hyunlee 1030
I don’t think that you should mention about your masters in your resume. It would have been okay to mention it if you had followed that year in grad school with some more course work in another school and completed the degree. Since you did not graduate and receive a degree, I think it will be fine if you don’t mention it. Using words such as “stopped” puts your resume in a negative light and also raises unnecessary questions.
However, that year was an important part of your education so far, and you must have learnt quite a lot as you were the best in class. You should discuss about your masters in the additional essay. If you were involved in any extracurricular activities, make sure you discuss that as well, focusing on your accomplishments over participation. But most importantly, you will have to give a very good reason as to why you left your masters, halfway, when you were doing so well.
If you do mention it on your resume, mention only your grades and the university. Don’t mention the graduation year or the name of the degree. Only mention the period for which you were there. Don’t write ‘stopped’. Just show you were there for one year. You can clarify it in additional essays or during the interview.