SODIAL(R) Ultra Thin Touch Screen 8 Digit Solar Power Transparent Calculator Office Supply Touch screen, easy to use. It is very small, beautiful, and easy to carry, no matter you are out for traveling or playing, you could also bring it with you! Don't need any battery, just need a little sunshine then you could use this calculator, no matter you are indoor or outdoor. It is not only super easy to save money and very convenient.