Vietnamese educational system contain of these main stages: kindergarten, primary school (grade 1 – 5),
lower secondary school (grade 6 – 9), upper secondary school (grade 10 – 12), and higher education in which
the primary school and the lower secondary school are aimed to be compulsory for every citizen by Vietnamese
government. Therefore, we can also say that primary school and lower secondary school belong to primary
education. Basic concepts of science are introduced to students from these stages. The upper secondary school is
grouped as professional education (Duc 2008) from which most of the topics of the lower secondary stage is
repeated with deeper investigation.