Mr. Pen 12-digit solar calculator makes everyday math fast and easy for the office, primary school, the market, and home. Standard function calculator — perfect for basic numerical calculations anytime you need quick answers. Big, sensitive keys — easy-to-press buttons for smooth, fast data entry. Essential operations — add, subtract, multiply, and divide with confidence. Percent + MU key — calculate percentages easily, including MU key percent calculations with a single press. Backspace correction — fix mistakes quickly without restarting your entire calculation. Compact handheld size — portable 4.6" x 2.8" design that saves space but stays comfortable to use. Large 12-digit display — clear visibility from multiple angles for easy reading. Battery included + auto-off — runs on one LR1130 button cell battery (included) and powers down after 8 minutes of inactivity. Reliable daily helper — a simple, efficient calculator that keeps up with everyday tasks.