It may be necessary to provide any tangram picture cards (see NCTM illumination website on tangram activities at http://illuminations.nctm.org/LessonDetail.aspx?id=L168) in order for children to copy the shapes. Allowing children to copy each others' shapes is also recommended to enhance spatial senses. While copying the shapes, children can use the names of geometric shapes as well as position or direction words (e.g., "top," "below," "under," "right," "left," "slide," "flip," or "turn," as in the episode with Jenny and Hajun at the beginning of this article). This process encourages children to communicate mathematically.