Make tangram one line. Describing figures and visualizing what they look like when they are transformed through rotations or flips or are put together or taken apart in different ways are important aspects of geometry in the lower grades. This two-part tan gram example demonstrates the potential for high-quality experiences provided by computer "shape" environments for students as they learn concepts described in the Geometry Standard. Problem-solving tasks that involve physical manipulative as well as virtual manipulative afford many students an entry into mathematics that they might not otherwise experience. In this part, Tan gram Puzzles, students can choose a picture and use all seven pieces to fill in the outline. In the second part, Tan gram Challenges, students can use tan gram pieces to form given polygons.