Features: Scienticfic calculator with notepad 2 in 1 flip design, come with large lcd writing tablet and a pen, which allows you to take notes while calculating. You can press the delete button to erase the notes, and also can lock it to keep them. The calculator has all the buttons- you find on a standard scientific calculator, is very versatile, and can be used for children or even math majors. It contains more operations than basic scientific calculator, including integrals, derivatives, statistics and complex number calculations, etc. Foldable & portable calculator notepad is foldable, closed to dust, easy to store, and easy to carry. Ideal for junior & high school students, college students, and professional researche The main- screen is powered by solar where as the LCD requires a button cellCR2032) that is included. Specifications: Product Folded size: approx 162x81x175mm/6.38x3.19x6.89in Types: 991ES/ 991MS/ 991CNX LCD: 6.5inches Net weight of product: 153g Product gross weight: 255g Material: Environmentally friendly ABS Working temperature: 0-4 ℃ Input pressure 100x200g Display panel: LCD flexible LCD screen+calculator Solar energy+button cell CR2032 Font color: monochrome-bold handwriting Reflectivity: 25% -3% Package Includes: 1PC x LCD Calculator 1PC x Stylus- note: Due to the problems of lighting effects and shooting angles, there will be certain tolerances in the product, please understand. Please allow 0-1cm error due to the manual measurment.