A method includes: inputting information indicating power usage; generating a differential value between i) a first cumulative value of power usage corresponding to a first user ID and ii) a second cumulative value of power usage corresponding to a second user ID in a prescribed period; generating a first conversion value by converting the differential value to a use time of a first electric home appliance; generating a first electricity bill value by converting the differential value to an electricity bill; generating display data indicating that the first electricity bill value corresponds to the first conversion value; and transmitting the display data.