Mental rotation is positively related to arithmetic ability; however, the mechanism underlying this relationship remains unclear. The possible roles of working memory, place-value concept, and number line estimation in the correlation between mental rotation and whole-number computation were investigated. One hundred and fifty-five first-grade…

Sample materials from a primary training packet are included. The packets were developed as a part of a teacher development program aimed at improving elementary mathematics by giving teachers practical ideas. The sample student materials are drawn from the areas of geometry and oral mathematics. (PK)