摘要：AbstractAccording to Jordan et al. (2006), most researchers agree that number sense in young children can be defined as the ability to subtilize small quantities, to discern number patterns, to compare numerical magnitudes and estimate quantities, to count, and to perform simple number transformations. Number sense, as assessed byNSB - Number Sense Brief Screener(Jordan, Glutting et al., 2008), is a powerful predictor of later mathematics outcomes at the end of first and third grades (Jordan et al., 2010). The results of Jordan et al. (2010) are in consonance with those of other investigations, suggesting that weaknesses in number competences concerning to counting, number relationships, and basic operations underlie most mathematics learning difficulties (e.g. Gersten et al., 2005; Geary et al., 2007; Landerl et al., 2004). With this study we aim: 1) to adapt the NSB - Number Sense Brief Screener (Jordan, Glutting et al., 2008) for the Portuguese population in order to identify early learning difficulties of mathematics; 2) to analyze the predictive capacity of the battery at the end of first grade; and 3) by a longitudinal and qualitative study, to follow the mathematics learning trajectories during the first and second grade. After kindergarten and at the moment of first grade initiation we measured number sense in Portuguese public schools’ children (n=860, average 6.43 years old). At the present moment we are on the process of the multi-year longitudinal investigation of children's mathematics development. The preliminary NSB results suggest that first-grade lower performance NSB group exhibits weak counting procedures, weak number comparisons (e.g. identify numbers in a numerical sequence), and inaccurate verbal problems’ resolution. Presently we are extending the number of participants; nevertheless, the findings indicate that screening early number sense development is useful for identifying children who will face later math difficulties which support the previous studies of Jordan et al. (2006; 2007; 2008).
