The teaching and learning fractions is one of the most problematic areas in primary school mathematics. A large number of studies have engaged paper-and-pencil test to measure students' instrumental understanding about fractions but few have sought to learn about children's fraction sense. This paper reports a study that investigated fraction sense possessed by the Malaysian primary pupils. A 16-item Fraction Sense Test (FST) was developed and administered to a group of 198 Primary 4 pupils to test their fraction sense in solving problems about fractions. From the FST result, six respondents were selected from the low ability, intermediate ability, and high ability group. These respondents underwent a series of clinical interviews. Results show that the low and intermediate achievers lack fraction sense. The high achievers demonstrated flexibility in visualizing and recognizing the representations of unfamiliar fractions. They developed mental referents for fractions. They noticed the number of parts and were aware that these parts must be equal when comparing fractions. They could visualize and perform operations mentally with larger value numerators and denominators. They have good sense of estimation and applied equivalence of fractions. These findings are useful to teachers who prepare teaching activities to enhance fraction sense.

Purpose – Most literature has focused solely on either knowledge about number sense or understanding of fractions. To fill the research gap, this study examined pupils’ abilities in both number sense and fractions. In particular, it investigated Year 4 and Year 5 pupils’ use of strategies in developing their fraction sense. Methodology – This study adopted a descriptive research design, utilising a mixed approach in data collection. An instrument called the Fraction Sense Test (FST) and a clinical interview were used to collect data. The FST comprised 3 strands: fraction concept, fraction representation and effect of operation. A two-stage cluster sampling method was employed to select 396 Year 4 and Year 5 pupils. The sampling involved random selection of the primary schools in the first stage, followed by pupils within the selected schools in the second stage. In addition to descriptive statistics, content analysis of interview transcripts was conducted to identify the presence of concepts and strategies applied among the pupils. Findings – The study found that the pupils scored lowest in effect of operation. It was also revealed that there were four strategies which helped the pupils to develop fraction sense, namely (1) comparing fractions using benchmark fractions of common fractions such as ½, ¼, zero and 1, (2) understanding denominators to determine the size of equal parts, (3) comparing fractions using unit fraction, and (4) applying the strategies in (1) and (2) to manipulate fractions in effect of operation. Significance – The findings provide useful input to facilitate the development of fraction sense ability.