The present study was designed to examine the effects of experience of learning support for school children on understanding of children’s mathematical difficulties. Elementary school teacher education course students participated in this study. They were divided into a group with the experience of the cognitive counseling (EX-group) and the group without the experience (N-EX-group). Examples of the erroneous answer for the arithmetic problem were presented to participants and they were requested to answer reason of error and a method of the learning support as much as possible. The result showed that EX-group was able to answer many reasons and support methods more than N-EX-group. These results were discussed in terms of ability formation of the learning support.