Fractions pose significant challenges for many children, but for some children those challenges persist into high school. Here we administered a fractions magnitude comparison test to 122 children, from Grades 4 to 8, to test whether their knowledge of fractions typically learned early in the sequence of formal math instruction (e.g., fractions…

Recent research on children's conceptual and procedural knowledge has suggested that there are individual differences in the ways that children combine these two types of knowledge across a number of mathematical topics. Cluster analyses have demonstrated that some children have more conceptual knowledge, some children have more procedural…

Research to date has proposed four main variables involved in reading development: phonological awareness, naming speed, orthographic knowledge, and morphological awareness. Although each of these variables has been examined in the context of one or two of the other variables, this study examines all four factors together to assess their unique…

When children learn to count and acquire a symbolic system for representing numbers, they map these symbols onto a preexisting system involving approximate nonsymbolic representations of quantity. Little is known about this mapping process, how it develops, and its role in the performance of formal mathematics. Using a novel task to assess…

The influence of orthography on children's online auditory word recognition was studied from the end of Grade 4 to the end of Grade 9 by examining the orthographic consistency effect in auditory lexical decision. Fourth-graders showed evidence of a widespread influence of orthography in their spoken word recognition system; words with rimes that…

This current study introduced a new method to investigate the prevalence and correlates of significant imbalances in the relative accuracy with which eighth-graders read nonwords (e.g., "prauma") and exception words (e.g., "vaccine"). Substantial proportions of students showed imbalanced word-reading profiles, but these were not strongly tied to…

Previous studies have shown that even preschoolers can solve inversion problems of the form a + b - b by using the knowledge that addition and subtraction are inverse operations. In this study, a new type of inversion problem of the form d x e [divided by] e was also examined. Grade 6 and 8 students solved inversion problems of both types as well…