Counting-On, Trading and Partitioning:

Factors affecting performance on Base-10 tasks were investigated in a series of four studies with a total of 453 children aged five to seven years. Training in counting-on was found to enhance child performance on Base-10 tasks (Studies 2, 3, and 4), while prior knowledge of counting-on (Study 1), trading (Studies 1 and 3) and partitioning (Studies 1 and 4) were associated with enhanced Base-10 performance. It emerged that procedural knowledge of counting-on, trading and partitioning can lead to improvements in procedural knowledge of the Base-10 system. The findings lend support to the model of iterative development of conceptual and procedural knowledge advanced by Rittle-Johnson, Siegler and Alibali (2001).