Children with mathematical difficulties need to spend more time than typically achieving children on solving even simple equations. Since these tasks already require a larger share of their cognitive resources, additional demands imposed by the need to switch between tasks may lead to a greater decline of performance in children with mathematical…

This book presents the first results from the third cycle of the IEA International Computer and Information Literacy Study (ICILS 2023). This study investigated how young people are prepared for life in a world where the capacity to use computers and digital information responsibly, safely, and effectively is essential. The study reports on data…

External number representations are commonly used throughout the first years of instruction. The twenty-frame is a grid that contains two rows of 10 dots each, and within each row, dots are organized in two groups of five. The assumption is that children can make use of these structures for enumerating the dots, rather than relying on one-by-one…

In a German out-of-school laboratory, 293 medium-achieving 10th-grade students participated in a lesson unit about gene technology. They were divided into two groups (I-1, I-2), both of which followed the same hands-on lesson procedure. Students within I-2 were additionally confronted with alternative conceptions to central issues of the specific…

Three experiments investigated the route-angularity effect, which is demonstrated when a greater number of turns along a route increases the estimated length. So far, a route-angularity effect has not been demonstrated in school-age children. Because of the lack of a developmental theory, this finding could only be explained by a minor control of…