An electronic calculator comprising: a display module in which digit grouping display members and decimal point display members are arranged in the upper part and lower part of a plural-digit number display member; a display pattern storage for storing display patterns according to a decimal point, shapes of symbols used for digit grouping, and the difference between decimal scaling positions displayed together with a number on the display module, wherein the stored display patterns include: a first display pattern, wherein three-digit grouping is performed by prime display members (19d, 19g, 19j) and a decimal point is represented by a period display member, a second display pattern, wherein three-digit grouping is performed by comma display members (18d, 18g, 18j) and the decimal point is represented by a period display member, a third display pattern, wherein three-digit grouping and subsequent two-digit grouping are performed by prime display members (19d, 19f, 19h, 19j, 19i) and the decimal point is represented by a period display member, a fourth display pattern, wherein three-digit grouping and subsequent two-digit grouping are performed by comma display members (18d,18f,18h,18j,18i) and the decimal point is represented by a period display member, a fifth display pattern, wherein three-digit grouping is performed by prime display members (19d,19g,19j) and the decimal point is represented by a comma display member, and a sixth display pattern, wherein three-digit grouping is performed by period display members (17d,17g,17j) and a decimal point is represented by a comma display member; a display pattern selection unit for selecting two types of display patterns according to user operation from the display patterns stored in the display pattern storage; a selected display pattern storage for storing the two types of display patterns selected by the display pattern selection unit; and a display pattern switching unit for switching the two types of display patterns stored by the selected display pattern storage according to user operation. a display module in which digit grouping display members and decimal point display members are arranged in the upper part and lower part of a plural-digit number display member; a display pattern storage for storing display patterns according to a decimal point, shapes of symbols used for digit grouping, and the difference between decimal scaling positions displayed together with a number on the display module, wherein the stored display patterns include: a first display pattern, wherein three-digit grouping is performed by prime display members (19d, 19g, 19j) and a decimal point is represented by a period display member, a second display pattern, wherein three-digit grouping is performed by comma display members (18d, 18g, 18j) and the decimal point is represented by a period display member, a third display pattern, wherein three-digit grouping and subsequent two-digit grouping are performed by prime display members (19d, 19f, 19h, 19j, 19i) and the decimal point is represented by a period display member, a fourth display pattern, wherein three-digit grouping and subsequent two-digit grouping are performed by comma display members (18d,18f,18h,18j,18i) and the decimal point is represented by a period display member, a fifth display pattern, wherein three-digit grouping is performed by prime display members (19d,19g,19j) and the decimal point is represented by a comma display member, and a sixth display pattern, wherein three-digit grouping is performed by period display members (17d,17g,17j) and a decimal point is represented by a comma display member; a display pattern selection unit for selecting two types of display patterns according to user operation from the display patterns stored in the display pattern storage; a selected display pattern storage for storing the two types of display patterns selected by the display pattern selection unit; and a display pattern switching unit for switching the two types of display patterns stored by the selected display pattern storage according to user operation. a first display pattern, wherein three-digit grouping is performed by prime display members (19d, 19g, 19j) and a decimal point is represented by a period display member, a second display pattern, wherein three-digit grouping is performed by comma display members (18d, 18g, 18j) and the decimal point is represented by a period display member, a third display pattern, wherein three-digit grouping and subsequent two-digit grouping are performed by prime display members (19d, 19f, 19h, 19j, 19i) and the decimal point is represented by a period display member, a fourth display pattern, wherein three-digit grouping and subsequent two-digit grouping are performed by comma display members (18d,18f,18h,18j,18i) and the decimal point is represented by a period display member, a fifth display pattern, wherein three-digit grouping is performed by prime display members (19d,19g,19j) and the decimal point is represented by a comma display member, and a sixth display pattern, wherein three-digit grouping is performed by period display members (17d,17g,17j) and a decimal point is represented by a comma display member; a display pattern selection unit for selecting two types of display patterns according to user operation from the display patterns stored in the display pattern storage; a selected display pattern storage for storing the two types of display patterns selected by the display pattern selection unit; and a display pattern switching unit for switching the two types of display patterns stored by the selected display pattern storage according to user operation.