Algebra in school, - a study on students` algebraic knowledge of the field equations in ninth grade.International (TIMSS) and national mathematics studies detects that Swedish pupils math skills is deteriorating in comparison to other countries. Therefore has the subject of mathematics become one of the school subjects which are becoming increasingly in focus. The government has made a big effort, Matematiklyftet, in mathematics in primary education, 650 million has been invested and the Agency has been tasked to train all current mathematics teachers through peer collegial learning. This effort is the most pervasive in modern times in Sweden.The aim of this study is that we as prospective mathematics teachers want to find our approach to surveys results. By using the Governments’ diagnoses, Diamant, student group interviews, teacher interviews and theories in mathematics education, we want to make students' algebraic knowledge of the field equations visible. This to understand how their knowledge in practice relate to international and national studies.