In order to reduce the frequency of rewriting pixels, gray scales of image signals input to a plurality of pixels provided in a display portion are checked before displaying each image. Specifically, in the case where image signals having medium gray scale levels are input to many of the plurality of pixels, display is performed by normal driving (for example, driving in which rewriting pixels is performed at a frequency higher than or equal to 60 times per second); otherwise, display is performed by driving with a small number of frequencies of rewriting pixels (for example, driving in which rewriting pixels is performed at a frequency lower than or equal to once per second). With this method, an information processing device which can reduce users' eye strain and perform eye-friendly display can be provided.