President Rouhani rang the bell in Hazrat Khadija school in District 18 of Tehran, where the female relatives of Iranian martyrs and war veterans study.
The school year started for 14.6 million students in 570,000 classrooms and 110,000 schools across the country.
The number of students going to school in Iran this year shows an increase of almost 500,000 compared to the last year.
Out of the 14.6 million students, some 8.2 million are primary pupils.
Students in Iran go to school for 10 months a year, or about 200 active days, from September to June. The average number of students per classroom is 20. From ages 7 to 18, boys and girls are educated separately. Then at the university, they experience co-education.
Beginning at age 7, all students must pass a yearly exam in order to move to the next grade level. Students in primary school learn about hygiene, basic math and science, reading, and study skills.