Mr. Pen desktop calculator makes daily calculations fast and comfortable with a large display and easy-to-press keys for home, school, and office use. 12-digit large display — clear visibility from multiple angles for confident reading. Standard function calculator — perfect for basic numerical calculations anytime you need quick answers. Big, sensitive keys — smooth, quick data entry with comfortable pressing. Essential operations — add, subtract, multiply, divide, and handle everyday math with ease. Percent + MU key — calculate percentages easily, including MU key percent calculations with a single press. Backspace correction — fix mistakes quickly without starting over. Desk-friendly size — compact 5.6 x 4.6 inches so it fits neatly on your workspace. Auto shutoff after 10 minutes — helps conserve battery life for longer use. Battery powered — runs on one AA battery (not included) . Reliable for everyday use — a simple, efficient desk calculator that keeps up with daily tasks.