1963 Volume 5 Issue 4 Pages 161-170
Number Ability Test, consisted of 6 items, was administered to 174 4- and 5-year-old children. The results showed the items were scalable (Green's I=.62), the most difficult being the item of conservation. 27 5-year-old children, who answered correctly except number conservation (NC), were selected as Ss and were divided into 3 groups. The following programs for an experimental education were applied one for each group: Repeated confirmation of invariance of a set by counting: Inference based on the change of the quantity by addition or subtraction: Inference based on the comprehension of number relations. The proportion of correct respondents to NC Test items markedly increased. The first program seemed the most effective.