The Casio DM-1200BM 12-Digit Extra Large Desktop calculator uses solar power, when light is sufficient while it uses battery power when light is insufficient. The 12-digit calculator has an extra large display for clear view and easy readability. Equipped with plastic keys, this calculator provides easy operation. The desk-top type calculator with rubber feet features metal faceplate that withstands rough treatment. It helps to calculate the cost, selling price or margin of profit on an item. The function command signs indicate the status of operation. This business calculator is ideal for the home or business office. It is the perfect size for an office desk.