Merton S. Keith was Helen's mathematics teacher. He also helped Helen with Greek and Latin. He lived in Cambridge, Massachusetts. For months, Mr. Keith tutored Helen twice a week. Eventually, he increased their instructional time to five one-hour sessions per week. Mr. Keith was a patient teacher. Helen felt that she was not bright in math, but despite this Mr. Keith "was always gentle and forbearing." He was a teacher who "made [math] interesting" and "he succeeded in whittling problems small enough to get through [her] brain." Math was one of Helen's weakest subjects, so her teacher simplified the content to make it easier for her to grasp. As Helen's entrance exams to Radcliffe College approached, Mr. Keith worked hard to prepare her. They were anxious about whether or not Helen would pass, but Mr. Keith remained devoted to helping his student. Helen passed and was able to enter Radcliffe. Mr. Keith continued to tutor her for one more year.