“…Among the reasons for the widespread use of the task is that studies found correlations between task performance and a wide range of other, more complex and advanced mathematical competence measures (see Siegler, , for a review). For example, number line estimation has been found to correlate with counting (Östergren & Träff, ), arithmetic (Torbeyns, Schneider, Xin, & Siegler, ), and standardized school achievement tests (Ashcraft & Moore, ). In several studies, the correlation remained significant after controlling for potential confounding variables, such as parental income and education, race, ethnicity, working memory, intelligence, reading achievement, nonsymbolic numerical knowledge, proportional reasoning, and arithmetic proficiency (Bailey, Siegler, & Geary, ; Geary, ; Hansen et al., ; Hornung, Schiltz, Brunner, & Martin, ; Jordan et al., ; Östergren & Träff, ; Vukovic et al., ).…”