The Flagship Carpets Addition and Subtraction Rug is a fun way to teach students basic math processes. The colorful number grid is a brightly shows the arithmetic answers as you follow the columns. Nylon fabric and serged edges make it a durable choice for your busy classroom. Color treatment prevents your rug from staining and fading, and anti-microbial protection keeps mold and bacteria from growing. Meets fire code safety requirements and has a lifetime warranty.