Vad är större: En Quarter Pounder eller en Third-Pound hamburgare?
Fractions, and calculations involving them, appear to be a difficult topic for students to grasp. Therefore, the purpose of this study is to investigate what secondary school teachers can do to improve their teaching practice regarding fractions. This paper is a literary study based on fraction related searches in academic data bases. It examines how fractions can be understood, and what types of misconceptions and difficulties that can be found among students all the way up to upper secondary school. It also presents what teachers, according to different research, should do to improve their teaching practice regarding fractions and how fractions were dealt with in ancient Egypt. We have found that students have several fraction-related misconceptions and difficulties, such as whole number bias or gap thinking. It appears that this is due to focusing too much on procedures instead of quality education focusing on building conceptual understanding. We conclude that education should highlight the differences between whole numbers and fractions, and focus on the measurement aspects of fractions rather than on part-whole relationships. A road to success for students struggling to understand fractions could be visualizing unit fractions and focusing on the sizes of unit fractions in relation to the number line, even when working with non-unit fractions.