Recent research has explored the numerical skills that acted as predictors of arithmetic fact knowledge. However, most of these studies suffer from some limitations. In some cases, arithmetic fact knowledge has been considered globally. In other cases the studies explored only the predictive role of one or two basic skills (e.g., Siegler & Opfer, 2008). Finally, some of these studies used a transversal methodology instead a longitudinal one. In the present research we explored the predictors of single-digit addition, subtraction and multiplication in a one-year longitudinal study. The basic numerical skills of 70 students were evaluated at the end of first-grade and their performance at arithmetic operations was measured at the end of second¬-grade. Regression analyses were carried out separately for each operation as criterion. The performance in a non-symbolic comparison task, an Arabic number comparison task, a transcoding task (dictation of one- and two-digit Arabic numbers), and a numerical sequence counting task were included as predictors. Results indicated differences between operations. Whereas for addition the predictor was the Arabic comparison task, the significant predictors for multiplication were the dictation of Arabic numbers and the non-symbolic comparison task. No significant predictors arose for subtraction. Results are discussed in relation to models of arithmetic fact processing and learning.
