Addition and subtraction strategies

Cilj ovoga rada jest predstaviti različite strategije zbrajanja i oduzimanja, kao i ukazati na važnost korištenja različitih pri rješavanju zadataka. Odabir strategija je adaptivan, on ovisi o djetetovom poznavanju određenih strategija i o obilježjima zadataka koje dijete rješava. Cilj rada je, također, predstaviti kognitivne strukture, odnosno mentalne slike, kao važan dio računanja. Način na koji djeca zamišljaju i predstavljaju manje brojeve, pridonosi lakšem prikazu većih brojeva i računskih radnji. Materijali Rechenschiffchen i Zwanzigerfeld pridonose izgradnji tih kognitivnih struktura. Istraživanje provedeno za potrebe ovoga rada temelji se na problematici izgradnje kognitivnih modela, a izvedeno je na materijalu Das Zwanzigerfeld mit Wendeplättchen. Istraživanje je provedeno u OŠ Mitnica Vukovar, a sudjelovalo je 37 učenika. Rezultati istraživanja pokazali su da su djeca radne skupine sposobna lakše prikazati i prepoznati određenu strukturu broja i/ili računske radnje. Manje strukture djeca puno lakše prepoznaju na pogled, a materijal je osobito pogodan za rad s djecom sa specifičnim poteškoćama u matematici i vizualnim tipovima učenika. Djeca češće koriste prikaz broja i računske radnje u redu.The purpose of this paper is to present different strategies of addition and subtraction as well as to point out the importance of using different strategies when solving tasks. The selection of strategies is adaptive, it depends on child's knowledge of about specific strategies, as well as on characteristics of the task which is being solved. Moreover, the purpose of the paper is to present cognitive structures, that is, mental images, as an important part of calculating. The way in which children imagine and present smaller numbers contributes to easier presentation of larger numbers and mathematical operations. The materials Rechenschiffchen and Zwanzigerfeld contribute to the construction of those cognitive structures. The research conducted for the purpose of this paper is based on the issue of construction of cognitive models, and it is carried out on the material Das Zwanzigerfeld mit Wendeplättchen. The research was conducted in primary school Mitnica Vukovar, with 37 pupils engaged. The results of the research have shown that the children of the working group are capable to easily II present and recognize the specific number and/or operation structure. Children easily recognize the smaller structures on sight, and the material is particularly suitable for working with children with specific difficulties in mathematics as well as for visual types of pupils. Children use the number presentation and operations in a line more often