According to andyeducation, the educational system in Iraq is organized into four levels: pre-primary, primary, secondary and tertiary. Pre-primary education is available to children between the ages of three and six. It comprises of educational activities that help prepare children for primary school. Primary education starts at the age of six and lasts for six years. During this period, students are taught basic subjects such as mathematics, science, language arts, social studies and religious studies. Secondary education follows primary education and lasts for three years. At this level, students are introduced to more specialized subjects such as history, geography, physics, chemistry, biology and foreign languages. Tertiary education in Iraq consists of diploma or degree programs offered by universities or other higher learning institutions. Admission into these programs usually requires a high score on the national university entrance exam as well as completion of secondary school with good grades. Programs offered at the tertiary level include courses such as business administration, engineering studies or medical sciences. In addition to university study programs there are also technical and vocational training institutes that offer specialized courses such as accounting or computer science related fields. Iraq also offers opportunities for adult education through various non-formal learning centers located throughout the country which provide courses in literacy skills and vocational training in areas such as carpentry or electrical engineering among others. Additionally some universities offer evening classes for those who wish to pursue higher education but cannot attend daytime classes due to work commitments or family responsibilities. See educationvv for Iraq educational systems.