<p>One hundred and twenty children between 3 and 5 years of age were examined to investigate how the solutions of problems based on the operations of union, complement and intersection is affected by the manner of presentation. The critical variables color, form and size were used to control presentation. Statistically significant associations were found between age and operations. The operations of intersection showed significant differences according to the manner of presentation used. The variable size, in all the ages studied, produced lower scores than the other variables. The operations of union and complement did not show significant differences across ages. The results seem to verify previous finding of the same author.</p>