Nail board is a classic geometry and arithmetic enlightenment teaching tool, consisting of a wooden board (or plastic board) covered with evenly arranged nails and colored rubber bands. The nails are distributed in a grid pattern with equal spacing, making it convenient to enclose various shapes with rubber bands. In lower grade teaching, students use rubber bands to enclose squares, triangles, etc., and intuitively understand the characteristics of the shapes; Senior students can advance to enclose symmetrical shapes, complex polygons, and understand geometric transformations. Teaching aids are flexible in operation and can transform abstract geometric concepts into concrete shapes. They are practical tools for cultivating spatial concepts and combining numerical .