ELECTRONIC CALCULATOR DISPLAYABLE WITH REPEATING DECIMAL

• US 20090113339A1
• Filed: 10/29/2008
• Published: 04/30/2009
• Est. Priority Date: 10/31/2007
• Status: Abandoned Application

• Current Assignee: Casio Computer Company Limited
• Original Assignee: Casio Computer Company Limited
• Inventors: UEJIMA, Hiroshi, NISHIZAKA, Nobuyoshi, MIYAZAWA, Yoshinaga, MIDOROGI, Satomi, GOTOH, Fumio
• Application Number:
  US12/260,288
• Publication Number:
  US 20090113339A1
• Time in Patent Office: Days
• US Class Current: 715/784
• CPC Class Codes: G06F 15/02 manually operated with input through keyboard and computation using a built-in program, e.g. pocket calculators
• CPC Class Codes: G06F 3/0485 Scrolling or panning
• CPC Class Codes: G09G 5/22 characterised by the display of characters or indicia using display control signals derived from coded signals representing the characters or indicia, e.g. with a character-code memory
• CPC Class Codes: G09G 5/34 for rolling or scrolling

Abstract

An electronic calculator includes: a display device; a user interface; a memory device; and a processor that is operable with the memory device to: perform a calculation to convert a fractional number into a decimal number; control the display device to display the decimal number, when the decimal number is a repeating decimal, with a symbol indicating a periodic block included in the repeating decimal control the display device to display a scroll indicator indicating that the displayed repeating decimal is scrollable when the number of digits included in the repeating decimal overflows the number of digits displayable by the display device; control the display device to display an undisplayed part of the repeating decimal to scroll in when a scroll command is input by the user through the user interface while the scroll indicator is displayed.

Claims

1. An electronic calculator comprising:

a display device that displays characters including numerical characters;

a user interface that allows a user to input operational commands;

a fractional number display module that controls the display device to display a given fractional number;

a conversion module that converts the fractional number into a decimal number;

a repeating decimal determination module that determines whether the decimal number is a repeating decimal;

a decimal number display module that controls the display device to display the decimal number;

a periodic block indication module that controls the display device to display a symbol with the decimal number when the repeating decimal determination module determines that the decimal number is the repeating decimal, the symbol indicating a periodic block included in the repeating decimal;

a display digit determination module that determines whether the number of digits included in the repeating decimal overflows the number of digits displayable by the display device;

an indicator display module that controls the display device to display a scroll indicator indicating that the displayed repeating decimal is scrollable when the display digit determination module determines that the number of digits included in the repeating decimal overflows the number of digits displayable by the display device; and

a scrolling display module that controls the display device to display an undisplayed part of the repeating decimal to scroll in when a scroll command is input by the user through the user interface while the scroll indicator is displayed.

2. The electronic calculator according to claim 1, wherein the periodic block indication module comprises:

a symbol storing module that stores a plurality of types of symbols for indicating the periodic block to be used in each countries or regions where the electronic calculator is used; and

a symbol setting module that sets one of the plurality of types of symbols to be used for indicating the periodic block in accordance with a setting command input by the user through the user interface; and

wherein the periodic block indication module controls the display device to display the symbol of the type set by the symbol setting module with the decimal number when the repeating decimal determination module determines that the decimal number is the repeating decimal.

3. The electronic calculator according to claim 1 further comprising a digit number display module that controls the display device to display the number of digits included in the periodic block.

4. The electronic calculator according to claim 2 further comprising a digit number display module that controls the display device to display the number of digits included in the periodic block.

5. A computer-readable storage medium containing a sequence of instructions for a program executable by a computer system, the program comprising:

instructions for controlling a display device to display characters including numerical characters;

instructions for allowing a user to input operational commands;

instructions for controlling the display device to display a given fractional number;

instructions for converting the fractional number into a decimal number;

instructions for determining whether the decimal number is a repeating decimal;

instructions for controlling the display device to display the decimal number;

instructions for controlling the display device to display a symbol with the decimal number when determined that the decimal number is the repeating decimal, the symbol indicating a periodic block included in the repeating decimal;

instructions for determining whether the number of digits included in the repeating decimal overflows the number of digits displayable by the display device;

instructions for controlling the display device to display a scroll indicator indicating that the displayed repeating decimal is scrollable when determined that the number of digits included in the repeating decimal overflows the number of digits displayable by the display device; and

instructions for controlling the display device to display an undisplayed part of the repeating decimal to scroll in when a scroll command is input by the user through the user interface while the scroll indicator is displayed.

6. An electronic calculator comprising:

a display device that displays characters including numerical characters;

a user interface that allows a user to input operational commands;

a memory device that stores data for a calculation; and

a processor that is operable with the memory device to;

perform the calculation to convert a fractional number into a decimal number;

control the display device to display the decimal number, when the decimal number is a repeating decimal, with a symbol indicating a periodic block included in the repeating decimal;

control the display device to display a scroll indicator indicating that the displayed repeating decimal is scrollable when the number of digits included in the repeating decimal overflows the number of digits displayable by the display device; and

control the display device t display an undisplayed part of the repeating decimal to scroll in when a scroll command is input by the user through the user interface while the scroll indicator is displayed.