The development of numerical abilities was examined in 59 children aged 5 years divided into three groups: one control group (n = 15) and two experimental groups (pencil-and-paper mathematical training: n = 29: computerized mathematical training: n = 15). The participants were assessed both before and after a battery of validated tests assessing numerical abilities (BIN test) and fluid intelligence (CPM test). The three groups showed similar values in the pre-test assessment regarding these two dimensions. A gain between post-test and pre-test scores was calculated; this result underlines significant differences between experimental groups and the control group in the four areas evaluated by the BIN test. This study shows the efficacy of both computer-assisted and pencil-and-paper training in enriching numerical intelligence; pencil-and-paper mathematical training seems to be more effective in some areas. This aspect leads us to reflect about this result and to deepen the research with subsequent experiments. [For the complete proceedings, see ED608557.]