Nigeria has a 1-6-3-3 formal education structure. There is one year of pre-primary school, which has an official entry age of five and is referred to as pre-primary education. Primary school, which is known as primary education, has an official entry age of six and a duration of six grades. At the end of the cycle, students sit for the Primary School Leaving Examination. Secondary school is divided into two cycles: lower secondary and upper secondary.
Lower secondary, which is known as junior secondary, consists of grades 7-9 and culminates in the Junior Secondary School Certificate; upper secondary, which is known as senior secondary, consists of grades 10-12 and culminates in the West African Senior School Certificate (WASSC) or the National Examinations Council (NECO) Certificate. In addition, Nigeria has an early childhood care development and education (ECCDE) program that has a theoretical entry age of six months and can last up to four years. There are also two lower secondary vocational education tracks that each last two years, and two upper secondary vocational education tracks that last up to three years (ISCED 2011 mapping for 2014 school year).