Item Type: Calculator Writing Tablet Material: LCD, ABS Color: White Product Size: Approx. 16 x 9.3 x 1cm / 6.3 x 3.7 x 0.4in (Manual Measurement, There is a Small Error) Battery Type: Button Battery (Built-In Battery) Battery Model: CR2032 Battery Capacity: 240mAh Voltage: 3V 1、Calculator and notepad are integrated design, you can take notes and draw while calculating, which can improve study and work efficiency.  2、No blue light LCD screen protects eyes. And can write repeatedly, reduce paper consumption, and environmentally friendly.  3、The calculator supports the calculation of up to 12 digits. Below the calculator is a writing board, which is very convenient for taking notes.  4、Small in size, easy to carry, and you can put this calculator in your pocket, which is convenient for taking phone calls, notes, and meeting minutes.  5、Made of high‑quality materials, and this calculator is sturdy, durable, not easily damaged, and has a long service life.