Mr. Pen 12-digit calculator is perfect for completing basic numerical calculations, making it ideal for office, primary school, market, or even home use. It features big, sensitive keys that are easy to press down and offer quick data entry. It allows you to add, subtract, multiply, divide and even calculate percentages with a single press of the MU key. The backspace function ensures that you can easily revise any errors without having to start again completely. Mr. Pen calculator is portable and small in size at 6.2 x 4.4 inches, so it doesn't take up much desk space but is still comfortably sized for easy usage. It also has a large 12-digit display, increasing its visibility from any angle. This calculator runs on one AAA battery (not included), and to conserve battery life, it automatically switches off if not used for 10 minutes or more.