In this paper we describe a comparison between two different approaches to teach some algorithmic and computational thinking to children, mainly in 3 rd grade. Children's learning is taken into main consideration and we want to analyze the difficulties students encounter using the different approaches. Before that, an introduction is done, describing the research framework and methodology, offering the background for this research and outlining the larger research project from which the paper is derived. We then describe the tasks used and look at some examples of the difficulties children face, on one side dealing with the problem of abstract thinking while programming, and on the other having troubles relating more practical activity with what the calculator does.