The present invention provides a method for concealing a mark in a number including the following steps: separating a number into seven segments, concealing at least a mark in at least a segment of the number, and displaying the number in a display device. The non-aqueous electrolyte secondary battery further includes a reservoir member defining a reservoir space located adjacent to an end face of the electrode body, the reservoir space being used to hold the non-aqueous electrolyte forced out of the electrode body through the end face of the electrode body. A computer program product stores in a computer readable form a set of computer program instructions for directing at least one computer to process a text document. By increasing the temperature inside the furnace up to a temperature in a range of the melting temperature of the solder bumps and higher, the first solder bumps and the second solder bumps are melted and joined.