In the 1970s pupils normally took the General Certificate of Education, Ordinary Level examinations at the age of 16 and the General Certificate of Education, Advanced Level examinations at the age of 18. Up to ten subjects were taken at Ordinary Level, although five or six were the most common choice, and up to four subjects were taken at Advanced Level, although two or three were the most common choice. O Levels have now been replaced by the General Certificate of Secondary Education, which combines examinations with course work assessments.