Scientific Calculator with Notepad: Come with a 6.5 inch writing tablet and a pen, allowing you to take notes while calculating. Press the delete button to erase the notes, and also can lock it to keep it (Slide the LOCK KEY) Natural Writing Function: Can input/output the content in writting form and tabular statistics. Features 240 scientific functions, including statistics, algebra, and trigonometry, to handle complex calculations with ease Portable and Convenient: Lightweight and compact design makes it easy to carry around, ideal for school, office, or travel. Perfect for on-the-go students and busy professionals Dual Power: The replaceble coin battery is built in this scientific calculator. Also powered by solar energy so you don't need to worry about battery depletion