”JAG RÄKNADE MED FINGRARNA" -
en studie om elevers beräkningsstrategier i subtraktion i årskurs 3
The aim of the study is to investigate how students in third grade solve subtractions problems and what strategies they use. Earlier research (Neuman, 1987; Svenson & Sjöberg, 1982) has shown that students leave third grade without sufficient knowledge in simple arithmetic. After a diagnose with 43 students in two classes, the students with many incorrect answers or using long time to solve the problems were selected for an interview. 18 students from the two classes were interviewed and videotaped during the last semester in grade 3 (nine years old). In the study the student’s strategies solving subtraction problems with and without fingers were studied. Semi structured interview was used as method in the study. The student’s strategies were analyzed with variation theory (Marton, 2015). Variation theory as a theoretical tool makes it possible to analyze how students experience numbers in different ways. Result of the study show that 60 % of the students are using “double counting”/”keeping track” with fingers as strategy for solving simple subtraction problems. When using double counting the students tend to see numbers as single units instead of groups of number that can be composed or decomposed. Double counting/keeping track as the only strategy for solving addition and subtraction problems indicate that students can have difficulties developing advanced computational skills. Seven of the 18 students did not use fingers for computation but showed difficulties in solving the subtraction problems. There was no difference among the students using or not using fingers, both groups had problems and did not use effective strategies.