Abstract
Regarding first-grade strategy use, counting-on is widely promoted as an alternative to counting-all. However, there are concepts of initial arithmetic education that aim at developing derivation strategies systematically from the outset, skipping counting-on. This paper refers to an ongoing study that provides some empirical evidence in support of the latter approach. Students of four Austrian classes whose teachers participated in a professional development programme designed to promote derivation strategies were interviewed to ascertain their computation strategies at the end of first grade. We present first results comparing them to those of a previous study that, using the same tasks, examined a random sample of children whose arithmetic education followed a distinctly different pathway.