The phrase 'enrolled in the third' is correct and can be used in written English.
You could use it for example when describing someone's educational background, such as the sentence: "She enrolled in the third grade when she was six years old."
You must have two of the three prerequisite courses completed or in progress and be enrolled in the third.
His mother later married an Indonesian Muslim, and Obama spent five years in Jakarta, where he attended Catholic and Muslim schools and, according to The Los Angeles Times, was enrolled in the third and fourth grades as a Muslim.
Paige had spent two years in the third grade at Nicholson Elementary School before her mother transferred her, in fall 2003, to Walter Reed Elementary School, a mile away, where Paige was once more enrolled in the third grade.
Students enrolled in the third and fourth year in the Degree Course at the Education Faculty in a University in the North of Italy were given questionnaires aimed at gathering information about their preferences during two different periods regarding materials, crossing the results with the first proposals designed by the students during their practice teaching internships in local schools.
The program is open only to students enrolled in the Ph.D. program in political science at Columbia University or at Sciences Po. Applications are open to students enrolled in the third year of their doctoral studies (after receiving the M.A. degree for Columbia students, and in the first year of Ph.D. studies for Sciences Po students).
All of the students who participated in the experiment were 15 18 years old, enrolled in the third grade of high school, and were following the same syllabus.
About 1.2 million Californians enrolled in the first open enrollment, and they face a Dec. 15 deadline if they want to change coverage for Jan . 1
Employment of these mechanisms was associated with female gender, enrollment in a private medical college, and students enrolled in the first 2 years of medical school.
Twenty-seven student-teachers werewenrolledlled in the seventh semester of studies participated.
