Background: Learning trajectories (LTs) in early mathematics curriculum and teaching have received increasing attention (Baroody et al., 2019; Clements, 2007; Clements & Sarama, 2021; Maloney et al., 2014; Sarama & Clements, 2009). For example, LTs were a core construct in the National Research Council (2009) report on early mathematics…

Graphical representations (GRs) of the learning content are often used for instruction (Ainsworth, 2006). When used in learning technology, GRs can be especially useful since they allow for interactions across representations that are physically impossible, for instance by dragging and dropping symbolic statements into a chart that automatically…