Come with a 6-inch writing 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 . 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 is powered by button batterie. Calculator Notepad is foldable, closed to dust, easy to , and easy to carry. perfect for & high school students, college students, and professional researchers. Color: Black Material: ABS+Silicone Parameter: Product Name: Solar Scientific Calculator With Writing Material: ABS shell + silicone key Power supply mode: the calculator is by solar energy, and the 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 a little different from the real thing. The measurement allowed error is +/- 1-3cm.