The purpose of this study was to investigate how concept-focused mathematical discussions

supported by representations affect students’ conceptual understanding and use of

mathematical language in addition and subtraction in grade 2. The study was conducted as an

intervention study with both quantitative and qualitative elements. The main theoretical

framework of the study was Vergnaud’s (1982) theory of conceptual fields, complemented by

perspectives on language and sociocultural learning.

During the intervention, the students participated in teaching activities where concrete

materials, pictures, symbols, and mathematical discussions were used to make mathematical

relationships and concepts visible. Data collection consisted of pre- and post-tests, classroom

observations, and worksheets. The quantitative results were analyzed using paired t-tests in

JASP, while the qualitative material was analyzed based on the categories conceptual

understanding, mathematical language, and representations.

The results showed statistically significant improvements in the students’ test results and use

of mathematical concepts after the intervention. The qualitative findings also showed that the

students increasingly used subject-specific language and multiple representations in their

reasoning about addition and subtraction. The study indicates that concept-focused

instruction supported by representations can strengthen students’ mathematical understanding

in the early years of primary school. At the same time, further research is needed regarding

the long-term effects of this type of instruction.