3-in-1 Design: The solar calculator is equipped with a notepad and a pen. You can take notes while calculating without paper, which improves learning and work efficiency, saves time, and is more convenient. Dual Power Supply and 12-Digit Display: This is a calculator that supports battery (CR1220) and solar power, with two power supply methods it is more suitable for long-term use. The solar calculator is equipped with a 12-digit display and an LCD writing tablet. Portable and Slim: This upgraded calculator is slim and lightweight (only 115 grams). The foldable design protects the notepad surface and is easy to carry. You can put it anywhere, such as in school bags, briefcases, pockets, etc. Silent and One-Key Erase: This desk calculator uses silicone buttons to keep quiet during use. There is a button at the bottom of the writing tablet to clear the screen. Multifunctional Calculator: This multifunctional calculator can be used as a calculator and can also be used for drawing exercises. It is easy to use, suitable for students, teachers, and business people. We offer a 1-year warranty and 24-hour fast customer service. Please feel free to contact us if you have any questions.