Abstract

Statistical processes start with selecting the studied variable and collecting data. For organizing data, it is essential to carry out the tally of the observed values. In this paper, an approach based on the observed categories is considered, and different manipulative and pictorial strategies for the tally are analyzed, as well as their connection with frequency tables. Finally, an experience with pre-service teachers consisting of using manipulative charts of tallies as a previous step to statistical manipulative graphs is presented.