The CT666N Calculator manufactured by Citizen is an electronic handheld calculator with several advanced functions. The CT666N has a large, easy to read LCD display, which shows the results of calculations on a high-contrast white background. It has a two line display, with a 12-digit output shown on the top line, and a 14-digit input line on the bottom. It is powered by solar cells as well as a single AA battery. The calculator also features a ‘memory capacity’ that can store up to six numbers. It also has a 3-key memory functions including clear, recall, and return. It has many mathematical functions including trigonometric functions, logarithmic functions, and basic arithmetic. Furthermore, it includes a tax calculation function and a sign change function. The calculator also has a protective transparent cover and a rubber-like material on the bottom for a firm grip. This makes it a perfect choice for students, home use, work or travel.