According to an embodiment, an activity meter registers, based on an acceleration sensor and an output signal of the acceleration sensor when a tapping operation is performed, information on the tapping operation, detects generation of a tapping operation identical to the tapping operation corresponding to the registered information from the output signal of the acceleration sensor, and stores, when generation of the tapping operation identical to the tapping operation corresponding to the registered information is detected, time information when the identical tapping operation is generated in a memory.
