Computers and computer programs

Abstract

To provide a calculator and a calculation program capable of checking a calculation history including an intermediate calculation result already checked during entry of a formula.SOLUTION: A calculator includes a processing unit that causes to: store, in a storage unit, operation data including numerical values and operational symbols that have been input by a user; display, in a first display area, the input numerical values, the input operational symbols, and calculation results sequentially calculated on the basis of the input numerical values and the input operational symbols; display, in a second display area, a mathematical formula based on the input numerical values and the input operational symbols; and, in the case that the operational symbol is selected in the second display area, display, in the first display area, on the basis of the operation data stored in the storage unit, numbers represented by the selected operands, or in the case that the operational symbol is selected in the second display area, display, in the first display area, on the basis of the operation data stored in the storage unit, the numerical value or the calculation result that is displayed in the first display area when the operational symbol is input.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a computer and a computer program. [Background technology]

[0002] Some calculators, such as desktop calculators, have a history function that displays the history of numbers and arithmetic symbols entered by the user, allowing the user to check whether their input is correct. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-107772 Summary of the Invention [Problem to be solved by the invention]

[0004] Here, if an expression that consists of a series of arithmetic operations, such as "2 + 3 × 4 =", is entered, the calculator will perform the calculations in the order they were entered. Therefore, the calculator will output "20", which is the result of "2 + 3", multiplied by "4", to get "5". In this case, with a conventional history function, the calculator will display the pair of input "number" and "operation symbol" according to the user's operation. For example, in the previous example, the calculator will display "2[+]", "3[×]", "4[=]". In other words, with a conventional history function, the result of "2 + 3", "5", which the user could see while entering the formula, will not be displayed.

[0005] An object of the present invention is to provide a calculator and a calculation program that enable a user to check a calculation history including intermediate calculation results that could be checked while inputting a formula. [Means for solving the problem]

[0006] A first aspect of the present invention provides a calculator that stores calculation data including numerical values ​​and operation symbols input by a user in a memory unit, displays the input numerical values, the input operation symbols, and calculation results calculated sequentially based on the input numerical values ​​and operation symbols in a first display area of ​​the display unit, displays a mathematical formula based on operands and operation symbols representing the input numerical values ​​in a second display area different from the first display area of ​​the display unit, and, based on operation of the operation unit by the user, selects an operand or operation symbol in the displayed mathematical formula in the second display area, and, when an operand symbol is selected in the second display area, displays the numerical value represented by the selected operand symbol in the first display area based on the calculation data stored in the memory unit, and, when an operation symbol is selected in the second display area, displays, based on the calculation data stored in the memory unit, the numerical value or calculation result that was displayed in the first display area at the time the operation symbol was input.

[0007] A calculation program according to a second aspect of the present invention causes a computer to execute the following operations: store calculation data including numerical values ​​and arithmetic symbols input by a user in a memory unit; display the input numerical values, the input arithmetic symbols, and calculation results calculated sequentially based on the input numerical values ​​and arithmetic symbols in a first display area of ​​a display unit; display a mathematical formula based on operands and arithmetic symbols representing the input numerical values ​​in a second display area different from the first display area of ​​the display unit; select an operand or arithmetic symbol in the displayed mathematical formula in the second display area based on operation of an operation unit by a user; and, when an operand is selected in the second display area, display the numerical value represented by the selected operand in the first display area based on the calculation data stored in the memory unit; and, when an arithmetic symbol is selected in the second display area, display the numerical value or calculation result that was displayed in the first display area at the time the arithmetic symbol was input in the first display area based on the calculation data stored in the memory unit. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a calculator and a calculation program that enable a calculation history to be checked, including intermediate calculation results that could be checked while inputting a formula. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram illustrating an example of the configuration of a computer according to an embodiment. [Figure 2] FIG. 2 is a front view showing the external configuration of the computer according to the embodiment. [Figure 3] FIG. 3 is a diagram showing an example of a display after a formula has been input by the user. [Figure 4] FIG. 4 is a flowchart showing the history mode process. [Figure 5] FIG. 5 is a diagram showing the transition of the display in the history mode. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, an embodiment will be described with reference to the drawings. FIG. 1 is a diagram showing an example of the configuration of a calculator 1 according to an embodiment. Calculator 1 has a processor 11, a memory 12, operation keys 13, and a display 14. Calculator 1 is, for example, a calculator. However, calculator 1 may be various electronic devices other than a calculator that have a function for calculating numerical values. For example, calculator 1 may be a terminal such as a smartphone on which a calculation application program is installed.

[0011] The processor 11 is a processor that controls various operations of the computer 1. The processor 11 may be a CPU, an ASIC, an FPGA, etc. The processor 11 may also be configured with two or more processors.

[0012] The memory 12 includes RAM and ROM. RAM is a volatile memory that can operate as a storage unit. RAM is used as a working memory for temporarily storing various data in the processor 11. In the embodiment, the RAM stores not only the data of numerical values ​​and arithmetic symbols input by the user, but also the calculation results each time a calculation is executed. That is, in the embodiment, the RAM has a formula storage area, which is a storage area for storing the data of the input values ​​and arithmetic symbols in the order of input, and a calculation result storage area for storing the calculation results in the order of calculation, including the calculation results obtained while inputting the calculation formula. The ROM is a non-volatile memory. Various programs, such as calculation programs for executing various calculation functions, are stored in the ROM.

[0013] The operation keys 13 include various physical keys for the user to operate the calculator 1. When an operation using the operation keys 13 is accepted, an input signal corresponding to the operation is transmitted to the processor 11.

[0014] The display 14 is a display unit such as a liquid crystal display, etc. The display 14 displays various information related to the calculator function.

[0015] FIG. 2 is a front view showing the external configuration of the calculator 1 according to the embodiment. The display 14 is, for example, a monochrome reflective liquid crystal display panel. The display 14 has two display areas: a 7-segment display 141 and a dot-matrix display 142. The 7-segment display 141 is, for example, a display with 10-digit 7-segment displays and a decimal point segment. The 7-segment display 141 is located in the lower section of the display 14. The 7-segment display 141 displays numerical values, arithmetic symbols, and calculation results of mathematical expressions input by the user. The dot-matrix display 142 is a display that can display higher resolution than the 7-segment display 141, which has dot-like pixels arranged two-dimensionally. The dot-matrix display 142 is located in the upper section of the display 14. The dot-matrix display 142 displays a calculation history, including mathematical expressions corresponding to the numerical values ​​and arithmetic symbols input by the user. In FIG. 2, the display 14 is configured with two different displays. In contrast, the display 14 does not necessarily have to be composed of two different displays, as long as it has a first display area that displays the calculation results of the numbers, arithmetic symbols, and formulas entered by the user, and a second display area that displays the calculation history including the formulas corresponding to the numbers and arithmetic symbols entered by the user.

[0016] The calculator 1 also has operation keys 13, including numeric keys 131, operation symbol keys 132, and function keys 133. The numeric keys 131 are used to input numeric values. The numeric keys 131 include keys corresponding to the numeric values ​​"0" through "9," for example, and a decimal point key. The operation symbol keys 132 are used to input operation symbols used in basic calculations such as arithmetic operations. The operation symbol keys include keys corresponding to the operation symbols, such as "+," "-," "×," "÷," and "=". Here, the "=" key is used to input the operation symbol "=" and also functions as a calculation execution key. The function keys 133 are used to instruct the execution of specific functions related to the calculator 1. The function keys 133 include an "AC (all clear)" key for clearing all input in a formula, a "C (clear)" key for clearing only the most recent input, a "DEL (delete)" key for deleting input characters, and the like. Furthermore, the function keys 133 include a left cursor key 1331, a right cursor key 1332, and a correction key 1333, which are operation keys used when displaying the calculation history. The left cursor key 1331 is a key used to instruct moving the cursor displayed in the history mode for displaying the calculation history to the left. The right cursor key 1332 is a key used to instruct moving the cursor displayed in the history mode to the right. The correction key 1333 is a key used when correcting past inputs in the history mode.

[0017] Next, the operation of the history mode of calculator 1 will be explained using a concrete example. Here, it is assumed that the user inputs a formula prior to the operation of the history mode, resulting in the display shown in Figure 3. Figure 3 shows an example of what appears on display 14 when the user operates operation keys 13 of calculator 1 to input "2000," "+," "3000," "×," "4," and "=" into calculator 1. Below, we will briefly explain the operation leading up to the display shown in Figure 3.

[0018] First, upon receiving a numeric value "2000" input by the user, processor 11 stores the data of the value "2000" in the first storage area of ​​the formula storage area of ​​RAM and displays the input "2000" on 7-segment display 141. Processor 11 also displays a first numeric value display 1421, indicating that the first numeric value has been input, on dot-matrix display 142. First numeric value display 1421 displays an operand symbol representing the first numeric value input, such as a boxed "1." This first numeric value display 1421 allows only one character to be displayed even when a numeric value with many digits is input. As a result, the length of the formula displayed on dot-matrix display 142 can be shortened even when a numeric value with many digits is input. It goes without saying that instead of first numeric value display 1421, the numeric value "2000" input by the user may be displayed on dot-matrix display 142. Furthermore, the first numeric display 1421 may not be a boxed "1" but may be a display of other characters such as "A."

[0019] Next, processor 11 receives input of an arithmetic symbol "+" by the user and stores the data of the arithmetic symbol "+" in the second storage area of ​​the formula storage area of ​​RAM, and displays the input "+" on 7-segment display 141. Furthermore, processor 11 receives the input of the arithmetic symbol and performs a calculation. Then, processor 11 stores the calculation result "2000" in the first storage area of ​​the calculation result storage area of ​​RAM. Furthermore, processor 11 updates the display on 7-segment display 141 based on the calculation result. In reality, the calculation result based on the input up to this point is "2000," so the display is not updated. Furthermore, processor 11 displays on dot-matrix display 142 a first arithmetic symbol display 1422, which indicates that the first arithmetic symbol has been input. First arithmetic symbol display 1422 is, for example, a display of "+" input by the user. Since an arithmetic symbol is usually a single character, it does not need to be substituted with another single character like a numeric value. Of course, the first arithmetic symbol display 1422 may be a display of other characters, similar to the first numeric display 1421.

[0020] Next, upon receiving the input of "3000," processor 11 stores the data of the value "3000" in the third storage area of ​​the formula storage area of ​​RAM, and displays the input "3000" on 7-segment display 141. Processor 11 also displays second numeric display 1423, indicating that the second numeric value has been input, on dot matrix display 142. Second numeric display 1423 is, for example, a boxed "2." It goes without saying that instead of second numeric display 1423, the numeric value "3000" input by the user may be displayed on dot matrix display 142. Furthermore, second numeric display 1423 may not be a boxed "2," but may be a character different from first numeric display 1421, such as "B."

[0021] Next, processor 11 receives the input of "x" and stores the data of the arithmetic symbol "x" in the fourth storage area of ​​the formula storage area of ​​RAM, and displays the input "x" on 7-segment display 141. Furthermore, processor 11 receives the input of the arithmetic symbol and performs a calculation. That is, processor 11 performs the calculation "2000 + 3000." Then, processor 11 stores the calculation result "5000" in the second storage area of ​​the calculation result storage area of ​​RAM. Furthermore, processor 11 updates the display on 7-segment display 141 based on the calculation result. That is, processor 11 displays "5000," the calculation result of "2000 + 3000." Furthermore, processor 11 displays a second arithmetic symbol display 1424 on dot-matrix display 142, indicating that the second arithmetic symbol has been input. Second arithmetic symbol display 1424 is, for example, an "x" input by the user. Of course, the second arithmetic symbol display 1424 may be a display of other characters, similar to the first numerical display 1421 and the like.

[0022] Next, upon receiving the input of "4," the processor 11 stores the data of the value "4" in the fifth storage area of ​​the mathematical formula storage area of ​​the RAM, and displays the input "4" on the 7-segment display 141. The processor 11 also displays a third numerical value display 1425, indicating that the third numerical value has been input, on the dot matrix display 142. The third numerical value display 1425 is, for example, a boxed "3." It goes without saying that instead of the third numerical value display 1425, the numerical value "4" input by the user may be displayed on the dot matrix display 142. Furthermore, the third numerical value display 1425 may not be a boxed "3," but may instead be a display of another character, such as "C," different from the first numerical value display 1421 and the second numerical value display 1423.

[0023] Finally, upon receiving the input of "=", processor 11 stores the data of the operation symbol "=" in the sixth storage area of ​​the formula storage area of ​​RAM. Furthermore, upon receiving the input of "=", processor 11 performs a calculation. That is, processor 11 performs the calculation "5000 x 4." Then, processor 11 stores the calculation result "20000" in the third storage area of ​​the calculation result storage area of ​​RAM. Furthermore, processor 11 updates the display on 7-segment display 141 based on the calculation result. That is, processor 11 displays "20000," the calculation result of "5000 x 4." Furthermore, processor 11 displays a third operation symbol display 1426 on dot matrix display 142, indicating that the third operation symbol has been input. Third operation symbol display 1426 is, for example, a display of "=" entered by the user. Of course, third operation symbol display 1426 may display other characters, similar to first numeric display 1421, etc.

[0024] The display in Fig. 3 is carried out in the manner described above. Note that in Fig. 3, up to the third arithmetic symbol display 1426 is displayed. Depending on the length of the mathematical expression, the fourth numerical value display and the fourth and subsequent arithmetic symbol displays may also be displayed. The portion that cannot be displayed on the dot matrix display 142 may be displayed in a scrolling manner.

[0025] After the display shown in Fig. 3, the process for the history mode is carried out as shown in Fig. 4. Fig. 4 is a flowchart showing the history mode process.

[0026] In step S1, processor 11 determines whether left cursor key 1331 or right cursor key 1332 has been pressed. If it is determined in step S1 that left cursor key 1331 or right cursor key 1332 has been pressed, the process proceeds to step S2. If it is determined in step S1 that left cursor key 1331 or right cursor key 1332 has not been pressed, processor 11 terminates the process of Fig. 4. In this case, processor 11 returns to normal operation of calculator 1.

[0027] In step S2, the processor 11 transitions the operation mode of the computer 1 to the history mode.

[0028] In step S3, processor 11 determines whether the cursor key pressed in step S1 is left cursor key 1331. If it is determined in step S3 that the pressed cursor key is left cursor key 1331, the process proceeds to step S4. If it is determined in step S3 that the pressed cursor key is not left cursor key 1331, that is, is right cursor key 1332, the process proceeds to step S5.

[0029] In step S4, processor 11 moves the position of the cursor displayed on dot matrix display 142 of display 14 to the left. Then, the process proceeds to step S6. For example, the initial position of the cursor is a position between the position of the last arithmetic symbol display and the position of the first numeric value display. For example, the initial position of the cursor in the example of FIG. 3 is a position before the boxed "1" after the "=" display. In addition, in the embodiment, the last position and the first position of the cursor are assumed to be connected. Therefore, for example, when left cursor key 1331 is pressed at the initial position, the cursor is moved to the position of "=" as third arithmetic symbol display 1426.

[0030] In step S5, processor 11 moves the position of the cursor displayed on dot matrix display 142 of display 14 to the right. Then, the process proceeds to step S6. For example, when right cursor key 1332 is pressed at the initial position, the cursor is moved to the position of the boxed "1" as first numeric display 1421.

[0031] In step S6, processor 11 determines whether the current cursor position is in the numerical display portion. If it is determined in step S6 that the current cursor position is not in the numerical display portion, i.e., in the arithmetic symbol display portion, the process proceeds to step S7. If it is determined in step S6 that the current cursor position is in the numerical display portion, the process proceeds to step S8.

[0032] In step S7, processor 11 displays the calculation result up to the numerical value immediately before the arithmetic symbol at the current cursor position on 7-segment display 141. Thereafter, the process proceeds to step S9.

[0033] In step S8, processor 11 displays the numerical value of the current cursor position on seven-segment display 141. Thereafter, the process proceeds to step S9.

[0034] In step S9, processor 11 determines whether or not modification key 1333 has been pressed. If it is determined in step S9 that modification key 1333 has been pressed, the process proceeds to step S10. If it is determined in step S9 that modification key 1333 has not been pressed, the process proceeds to step S11. Here, in step S9, it is determined whether or not modification key 1333 has been pressed. Alternatively, it may be determined whether or not a specific key other than modification key 1333, such as a DEL key, has been pressed. In this case, modification key 1333 may not be present.

[0035] In step S10, processor 11 accepts a user's input to modify a numerical value or an arithmetic symbol. When a numerical value or an arithmetic symbol is input, the corresponding numerical value or arithmetic symbol data in the mathematical formula storage area is modified to the modified numerical value or arithmetic symbol data. Processor 11 also performs a calculation according to the modified mathematical formula, and modifies the calculation result data stored in the calculation result storage area to data based on the new calculation result. Then, the process proceeds to step S11.

[0036] In step S11, processor 11 determines whether to return from history mode. For example, it is determined that the history mode will be returned if a predetermined period of no operation continues, if a numeric key 131 is operated, or if a function key 133 such as the AC key or C key is operated. If it is determined in step S11 that the history mode will not be returned, the process returns to step S3. If it is determined in step S11 that the history mode will be returned, processor 11 ends the process of FIG. 4. In this case, processor 11 returns to normal operation of calculator 1.

[0037] FIG. 5 is a diagram showing the transition of the display in the history mode. For example, suppose that the left cursor key 1331 is pressed in the initial state shown in FIG. 3. In this case, the processor 11 displays a cursor 1427 below "=" as the third arithmetic symbol display 1426, as shown in FIG. 5a. The processor 11 also displays, for example, the character string "REV" on the 7-segment display 141 as the history mode display 1412 to notify the user that the operation mode has transitioned to the history mode due to the operation of the left cursor key 1331. Note that the history mode display 1412 is not limited to displaying the character string "REV." Furthermore, because the cursor 1427 is located in the arithmetic symbol display, the processor 11 displays the calculation result up to the immediately preceding numerical value on the 7-segment display 141. Specifically, the processor 11 retrieves the data of "20000", which is the calculation result up to the number immediately before "=", from the calculation result memory area, and displays "20000" as the calculation result value 1413 on the 7-segment display 141 based on the retrieved data.

[0038] Suppose that the left cursor key 1331 is then pressed. In this case, the processor 11 displays a cursor 1427 below the boxed "3" as the third numeric display 1425, as shown in FIG. 5B. Because the cursor 1427 is positioned within the numeric display, the processor 11 displays a numeric value corresponding to the numeric display on the 7-segment display 141. Specifically, the processor 11 acquires data for "4," which is the numeric value corresponding to the third numeric display 1425, from the mathematical formula storage area, and displays "4" as the numeric value 1414 on the 7-segment display 141 based on the acquired data. At this time, the processor 11 may further display "x" as the arithmetic symbol display 1415 paired with the third numeric display 1425 on the 7-segment display 141.

[0039] Then, suppose that the left cursor key 1331 is pressed again. In this case, the processor 11 displays a cursor 1427 below the "x" as the second arithmetic symbol display 1424, as shown in FIG. 5c. Furthermore, since the cursor 1427 is positioned within the arithmetic symbol display, the processor 11 displays the calculation result up to the immediately preceding numeric value on the 7-segment display 141. Specifically, the processor 11 obtains the data of "5000," which is the calculation result up to the numeric value immediately preceding the "x," from the calculation result storage area, and displays "5000" as the calculation result value 1416 on the 7-segment display 141 based on the obtained data. In this way, in the embodiment, intermediate calculation result values ​​can also be displayed during the history mode.

[0040] Similarly, the display on the 7-segment display 141 is updated sequentially in accordance with the operation of the cursor keys. Although not shown in Fig. 5, if the left cursor key 1331 is further pressed, for example, the processor 11 obtains the data for "3000", which is the numerical value corresponding to the second numerical value display 1423, from the mathematical formula storage area, and causes the 7-segment display 141 to display the numerical value "3000" based on the obtained data.

[0041] As described above, in the embodiment, when an arithmetic symbol is selected in the history mode, the calculation result up to the value immediately before the symbol is displayed. In other words, in the embodiment, the calculation result that the user was able to check while entering a formula can also be checked in the history mode. This further enhances convenience for the user.

[0042] In addition, in the embodiment, the display has two display areas consisting of a 7-segment display and a dot matrix display. Although a 7-segment display cannot display many characters, it can display large characters. Such a 7-segment display is suitable for displaying values ​​that a user may particularly want to check while entering a mathematical formula, such as input numerical values ​​and arithmetic symbols, and calculation results based on the input mathematical formula. Furthermore, a dot matrix display can display more details than a 7-segment display, which is suitable for displaying the entire mathematical formula. In this way, in the embodiment, the use of two types of displays allows for a history mode display that is highly convenient for the user.

[0043] In addition, in this embodiment, when a numerical value is input, a character representing the numerical value is displayed on the dot matrix display, so that the user can easily grasp the overall picture of the input mathematical expression even when the input numerical value has a large number of digits.

[0044] In addition, in this embodiment, by pressing the correction key in the history mode, the inputted numerical value or arithmetic symbol can be easily corrected, and the calculation is then performed again based on the corrected numerical value or arithmetic symbol.

[0045] In this embodiment, the calculation result, including the calculation result in the middle of input, is stored in the calculation result storage area. Alternatively, the calculation result in the middle of input does not have to be stored in the calculation result storage area. In this case, in step S7 when processor 11 determines that the current cursor position is in the calculation symbol display portion, processor 11 retrieves data up to the numerical value immediately before the calculation symbol at the current cursor position 1427 from the formula storage area, and performs recalculation using the retrieved data. Then, processor 11 displays the calculation result on 7-segment display 141.

[0046] The present invention is not limited to the above-described embodiments, and various modifications can be made in the implementation stage without departing from the spirit of the invention. Furthermore, the embodiments may be implemented in appropriate combinations where possible, and in such cases, the combined effects can be obtained. Furthermore, the above-described embodiments include inventions at various stages, and various inventions can be extracted by appropriately combining the disclosed multiple constituent elements. For example, if some constituent elements are deleted from all the constituent elements shown in the embodiments, and the problem stated in the "Problem to be Solved by the Invention" section can be solved and the effect stated in the "Effect of the Invention" section can be obtained, the configuration from which these constituent elements are deleted can be extracted as an invention.

[0047] Furthermore, each process according to the above-described embodiment can be stored as a program that can be executed by the processor 11, which is a computer. Alternatively, the program can be stored in a storage medium of an external storage device such as a magnetic disk, an optical disk, or a semiconductor memory and distributed. The processor 11 can then load the program stored in the storage medium of the external storage device, and its operation can be controlled by the loaded program, thereby executing the above-described process.

[0048] The inventions described in the claims of the present application as originally filed are set forth below. [1] storing operation data including numerical values ​​and operation symbols input by a user in a storage unit; displaying the input numerical values, the input operational symbols, and calculation results calculated sequentially based on the input numerical values ​​and operational symbols in a first display area of ​​a display unit; displaying a mathematical expression based on the operands and operators representing the input numerical values ​​in a second display area different from the first display area of ​​the display unit; selecting the operand symbol or the operator symbol in the displayed mathematical formula in the second display area based on a user's operation of an operation unit; when the operand symbol is selected in the second display area, displaying the numerical value represented by the selected operand symbol in the first display area based on the operation data stored in the storage unit; When the operation symbol is selected in the second display area, the numerical value or the calculation result that was displayed in the first display area at the time the operation symbol was input is displayed in the first display area based on the operation data stored in the storage unit. A computer having a processing unit. [2] The calculator according to [1], wherein the processing unit displays a character representing the input numerical value as the operand symbol in the second display area. [3] Further comprising an operation key for receiving an instruction to correct a numerical value or an arithmetic symbol selected in the second display area; the processing unit modifies a numerical value or an operation symbol stored in the storage unit corresponding to the selected operand symbol or operation symbol in accordance with an input after the operation of the operation key; [1] or [2]. [4] The processing unit stores the calculation result in the storage unit. [1]-[3]. [5] The calculator according to [4], wherein the processing unit further modifies the calculation result stored in the memory unit based on the modified numerical value or operation symbol. [6] storing calculation data including numerical values ​​and calculation symbols input by a user in a storage unit; displaying the input numerical values, the input operational symbols, and calculation results calculated sequentially based on the input numerical values ​​and operational symbols in a first display area of ​​a display unit; displaying a mathematical expression based on the operands and operators representing the input numerical values ​​in a second display area different from the first display area of ​​the display unit; selecting the operand symbol or the operator symbol in the mathematical formula displayed in the second display area based on a user's operation of an operation unit; When the operand symbol is selected in the second display area, the numerical value represented by the selected operand symbol is displayed in the first display area based on the operation data stored in the storage unit; When the operation symbol is selected in the second display area, the numerical value or the calculation result that was displayed in the first display area at the time the operation symbol was input is displayed in the first display area based on the operation data stored in the storage unit; and A calculation program that causes a computer to execute the above. [Explanation of symbols]

[0049] 1 calculator, 11 processor, 12 memory, 13 operation keys, 14 display, 131 numeric keys, 132 operation symbol keys, 133 function keys, 141 seven-segment display, 142 dot matrix display, 1331 left cursor key, 1332 right cursor key, 1333 correction key.

Claims

1. storing the calculation data including the numerical values ​​and calculation symbols input by the user in a storage unit; displaying the input numerical values, the input operational symbols, and calculation results calculated sequentially based on the input numerical values ​​and operational symbols in a first display area of ​​a display unit; displaying a mathematical expression based on the operands and operators representing the input numerical values ​​in a second display area different from the first display area of ​​the display unit; selecting the operand symbol or the operator symbol in the mathematical formula displayed in the second display area based on a user's operation of an operation unit; when the operand symbol is selected in the second display area, the numerical value represented by the selected operand symbol is displayed in the first display area based on the operation data stored in the storage unit; When the operation symbol is selected in the second display area, the numerical value or the calculation result that was displayed in the first display area at the time the operation symbol was input is displayed in the first display area based on the operation data stored in the storage unit. A computer having a processing unit.

2. 2. The computer according to claim 1, wherein the processing unit displays a character representing the input numerical value as the operand symbol in the second display area.

3. further comprising an operation key for receiving an instruction to correct a numerical value or an arithmetic symbol selected in the second display area; the processing unit modifies the numerical value or the operational symbol stored in the storage unit corresponding to the selected operand or operational symbol according to the numerical value or the operational symbol input by the user after the operation of the operation key; 3. The computer according to claim 1 or 2.

4. The processing unit stores the calculation result in the storage unit.

4. A computer according to any one of claims 1 to 3.

5. 5. The computer according to claim 4, wherein the processing unit further modifies the calculation result stored in the storage unit based on the modified numerical value or operation symbol.

6. storing calculation data including numerical values ​​and calculation symbols input by a user in a storage unit; displaying the input numerical values, the input operational symbols, and calculation results sequentially calculated based on the input numerical values ​​and operational symbols in a first display area of ​​a display unit; displaying a mathematical expression based on the operands and operators representing the input numerical values ​​in a second display area different from the first display area of ​​the display unit; selecting the operand symbol or the operator symbol in the mathematical expression displayed in the second display area based on a user's operation of an operation unit; When the operand symbol is selected in the second display area, the numerical value represented by the selected operand symbol is displayed in the first display area based on the operation data stored in the storage unit; When the operation symbol is selected in the second display area, the numerical value or the calculation result that was displayed in the first display area at the time the operation symbol was input is displayed in the first display area based on the operation data stored in the storage unit; and A calculation program that causes a computer to execute the above.

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