This study examines the possibility that children can learn how to make proportional judgements by using the 'half' strategy in a systematic way, and also to transfer its application to another proportional task which proved to be a difficult one. The experimental design consisted of a pre-test, a post-test, and a training procedure. One hundred and eighty children aged 6 to 8 years old were divided into three groups: task group, control group and training group. Only children who received the intervention did significantly better in the post-test than in the pre-test, and they were more successful in the post-test than children in the other groups. They were able to overcome their initial difficulties after training. The conclusion was that children can be taught how to make proportional judgements and that the 'half' strategy helps them to deal with the quantities and relations crucial to proportional reasoning.
Intervention; 'half' strategy; proportion; children