Number line estimation strategies

ABSTRACT The present study had the objective to verify which strategies were used the most by 30 children, from the 2nd to the 6th grade (six students of each class), of a public school in the city of Porto Alegre/RS, in order to perform in a number line estimation task, using individual semi-structured interviews. The main objective of this study was, besides describing the main strategies, to point out those that were more frequent and/or more precise. We have found eight different strategies, ranging from simple exact counting to more complex ones, involving multiplicative proportional structures. The results have indicated that the counting strategy was the one with the highest frequency of usage, but its use wielded low accuracy. For this test, students with higher levels of formal education used more complex strategies, not yet accessible to those with less formal education, which have made possible estimates that are more accurate.