Come with a 6-inch 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. 240 Kinds of computing functions, Include fractions, statistics, complex number calculations, linear regression, base arithmetic, computer science, standard deviation, -rectangular conversions, etc.. Adopt silicone material key, comfortable to touch. Power supply mode: the calculator is by solar energy, and the tablet is powered by button batterie. Calculator Notepad is foldable, closed to dust, easy to store, and easy to carry. perfect for junior & high school students, college students, and professional researchers. Color: Black Material: ABS+Silicone Parameter: Product Name: Solar Scientific Calculator With Writing Tablet Material: ABS shell + silicone key Power supply mode: the calculator is by solar energy, and the tablet is powered by button batteries Product folded size: 161 x 78mm Product expansion size: 161 x 156mm Package Contents: 1 x Solar Calculator Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.