JPH0736836A - Fractional computer - Google Patents

Abstract

PURPOSE: To provide a fractional computer understandably showing the calculating process of a fractional calculating expression. CONSTITUTION: The fractional computer 10 is provided with a liquid crystal display 12, a mode selection switch 14, a fraction specifying key 17 and an arithmetic input key 25 on the front surface of its main body 10a, and an internal control circuit is provided with an arithmetic logical unit, a data memory, an input part, an instruction decoder and a program memory. The data memory is provided with a progress flag Fc showing whether to display the halfway progress of fractional calculation and a next flag Fd to which a next processing content is set. Each time of pressing a 'next step' key 39 in the learning mode of fractional calculation, the calculating result to the halfway and the next processing content are displayed on the liquid crystal display 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fractional calculator for performing fractional calculation.

[0002]

2. Description of the Related Art In a fractional calculator of this type, an input key for instructing a fractional calculation is provided, and when the fractional calculation is designated by the input key, only the result of the fractional calculation is displayed.

[0003]

However, it is possible to display the correct answer when such a fractional calculator does not know the answer or when the answer is incorrect, but for those who are going to learn fractional calculation, Did not understand why such an answer would be given, and had reduced the learning effect of the fractional calculator. In particular, when learning fraction calculation, even though it is necessary to fully understand the calculation process such as divisor, divisor, and conversion of mixed fraction into improper fraction and then calculation of multiplication and division, these calculation processes Since there is no learning machine to teach, the learning of fraction calculation was difficult for elementary school students to understand.

Therefore, it is an object of the present invention to provide a fractional calculator that shows the calculation process of a fractional calculation formula in an easy-to-understand manner.

[0005]

In order to achieve the above object, the fractional calculator of the present invention is configured by a fractional setting means for inputting a value into a denominator and a numerator to set a plurality of fractions, and the fractional setting means. A plurality of fractions are provided with calculation formula setting means for setting a fraction calculation formula, calculation means for calculating the fraction calculation formula set by the calculation formula setting means, and display means for displaying the fraction calculation formula. In the fractional calculator, the calculating means includes a calculation stopping means for stopping the calculation in the progressing step of the fractional expression, and the displaying means displays the progressing step display for displaying the calculation of the progressing step stopped by the calculation stopping means. And means.

[0006]

In the fractional calculator of the present invention, the fractional setting means inputs values to the denominator and the numerator to set a plurality of fractions, and the fractional expression is set for the plurality of fractions set by the fractional setting means. Means for calculating the fractional calculation formula set by the calculation formula setting means by the calculation means, and displaying the fractional calculation formula by the display means, by the calculation stopping means provided in the calculation means. The calculation is stopped at the advancing stage of the fractional calculation formula, and the calculation of the advancing stage stopped by the calculation stopping means is displayed by the advancing step display means provided in the display means.

[0007]

Embodiments of the present invention will be described with reference to the drawings.

[First Embodiment] FIG. 1 is a perspective view showing the external appearance of a fraction calculator 10 according to the first embodiment. The fraction calculator 10 includes a liquid crystal display 12, a mode selection switch 14, a fraction designation key 17, and a calculation input key 25. Liquid crystal display 1
Reference numeral 2 indicates a calculation formula such as a fraction and the calculation result. The mode selection switch 14 can be switched to either a "fractional" mode for performing fractional calculations, a "normal" mode for performing ordinary calculations other than fractions, or a "learning" mode for practicing fractions. Calculation input key 25 is numeric keypad 21
, “×” key 40, “÷” key 41, “−” key 42,
It has four arithmetic operation keys such as a “+” key 43 and an “=” key 39. The fraction designation key 17 includes a “to” key 27 indicating a division between an integer part and a fraction part, a “minute” key 29 indicating a division between a denominator part and a numerator part, and a “provisional fraction” which alternately switches mixed fractions and improper fractions. "Key 32," division "key 35 for designating fraction reduction, and" division "key 3 for designating display of fraction calculation
8 are provided. The “=” key 39 is for instructing the execution of the calculation of the fractional formula, but when the mode selection switch 14 is in the “learning” mode, the calculation of the fractions, the totals, etc. is advanced one step at a time. "Key 39.

Next, the configuration of the control circuit 20 incorporated in the main body 10a of the fractional computer 10 will be described. First, the overall configuration will be described. FIG. 2 is a block diagram showing the overall configuration of the control circuit 20. The control circuit 20 includes an arithmetic logic unit (ALU) 59, a data memory (RAM) 5
4, a key input unit 62, a display unit 65, an instruction decoder 86 and a program memory 85. The key input unit 62 includes an input buffer 77 and an output buffer 7.
It has a keyboard 72 connected to a bus 71 via 8. This keyboard 72 has the above-mentioned mode selection switch 1
4, a fraction designation key 17 and a calculation input key 25 are assigned. The display unit 65 has the liquid crystal display 12 and the display decoder / driver 13 that drives the liquid crystal display 12, and displays the data stored in the data memory 54. The program memory (ROM) 85 has an address decoder 85a and stores an instruction at an address designated by the address decoder 85a. The instruction decoder 86 reads and decodes the instruction at the address specified by the address decoder 85a, and controls the above-mentioned respective parts in synchronization with a predetermined timing clock.

The control circuit 20 having the above-mentioned configuration specifically executes the following operation. When the data stored in the data memory 54 is transferred to the arithmetic logic unit 59 via the bus 71 and arithmetic processing is executed in the arithmetic logic unit 59, the result is stored again in the data memory 54 via the bus 71. Further, the data stored in the data memory 54 is transferred to the display decoder / driver 13, and the liquid crystal display 12 displays the transferred data. Alternatively, the mode selection switch 14 on the keyboard 72, the fraction designation key 1
7 or the operation input key 25 is operated, the signal is read from the input buffer 77 and the bus 7
The data is temporarily stored in the data memory 54 via 1 and the processing of the instruction corresponding to each key is executed.

Next, a detailed configuration of each part of the control circuit 20 will be described. FIG. 3 is a block diagram showing an internal configuration of the data memory 54. The data memory 54 stores a fraction area 54a for storing the fraction displayed on the liquid crystal display 12.
Is provided. In this fractional area 54a, the operation term X
In addition to the integer part Xa, the denominator part Xb, the numerator part Xc, the integer part Ya of the operand Y, the denominator part Yb, and the numerator part Yc, any of the integer part, the denominator part, and the numerator part is input during the input of the fraction. The input position flag Fa indicating whether the calculation is being performed, the progress flag Fc indicating that the learning process is in progress and the next flag Fd indicating the process to be performed next are areas 54b, 54c, 54d and 54f, respectively. 54 g, 5
It is assigned to 4h, 54i, 54j, and 54k.

Next, the structure of the display section 65 will be described. As described above, the display decoder / driver 13 of the display unit 65 drives the liquid crystal display 12 by the simple matrix driving method. FIG. 4 is a front view showing all the display segments 12a of the liquid crystal display 12. The total display segment 12a includes a numerical display unit 130 that displays numerical data and an auxiliary display item group 13 that displays terms related to fraction calculation.
Has 1. 5 and 6 show all display segments 12a
It is a connection diagram showing the connection of the common electrodes C1 to C8 and the segment electrodes S1 to S40. For example,
Common electrodes C1, C2, C3 and segment electrodes S1,
The display segment 13 that constitutes the "Japanese character" of the segment group 130a at the upper right end by the combination of S2 and S3
2, 133, 134, 135, 136, 137, 138
Can be selectively illuminated to display data. Common electrodes C3, C4, C5, C6 and segment electrodes S
Display segment 1 that constitutes the "day" character of the segment group 130b in the rightmost middle stage by the combination of 1, S2, and S3
38, 139, 140, 141, 142, 143, 14
4 can be selectively illuminated to display data.
Similarly, the display segments 144, 145, 146, 147, 148, 14 forming the "day" of the segment group 130c at the lower right end by the combination of the common electrodes C6, C7, C8 and the segment electrodes S1, S2, S3.
Data can be displayed by selectively illuminating 9,150. Similarly, data is displayed in the upper, middle, and lower columns of the second digit from the right end from the common electrodes C1 to C8 and the segment electrodes S4, S5, and S6. When the mixed number is displayed, the integer part is displayed in the middle part, the denominator part is displayed in the lower part, and the numerator part is displayed in the upper part. Thus, for example, display segment 138
Since is used for both the upper display and the middle display, it is not possible to display the upper and lower columns of the same digit when the middle display is displayed. Also, when the upper and lower columns are displayed, the middle column of the same digit cannot be displayed. By adopting such a display form, the display is very easy to see as shown in FIG. When the numerator and denominator data are displayed in the upper and lower rows, respectively, the display segment 141 in the middle row and the display segment 15 arranged in the same line between columns as the display segment are displayed.
A horizontal line that separates the denominator and the numerator is displayed at 1,152.

Next, the calculation process of the fraction calculation will be concretely described based on the display example of the liquid crystal display 12. First, a procedure for inputting a fraction using the fraction specifying key 17 and the operation input key 25 described above will be described. For example, the mixed number "34
When inputting "/ 7", the value "3" is input by the ten keys 21 and the "and" key 27 is pressed to confirm the input of the integer part. Then, after inputting the value "7", press the "minute" key 2
Confirm the denominator by pressing 9 and continue to the value “4”
Enter to confirm the numerator and complete the fraction input. In this way, since the key inputs are performed in the order of reading the mixed number, the operability is good. 7, 8 and 9 are flowcharts showing the fraction calculation routine. Further, FIG. 10 is an explanatory diagram showing a display mode of the liquid crystal display 12 which changes according to a key operation. First, when the execution of this routine is started, each storage area allocated to the data memory 54 is set to an initial value (step S110). Liquid crystal display 1
2 as the initial screen (step S120), and the keyboard 7
Wait for key input from 2 (step S130). what if,
It is assumed that the value "1" is input. Next, it is judged whether the mode selection switch 14 is in the "normal" mode or the "fractional" mode or the "learning" mode (step S140). When the "normal" mode is selected, the normal mode is selected. Calculation processing is performed (step S14)
5). Since this normal calculation process is well known, its detailed description will be omitted. Again, it returns to step S120 and repeats the same processing. When in the "fractional" mode or the "learning" mode, it is determined whether or not the progress flag Fc is set (step S147). If the progress flag Fc is set to "ON" and the mode is a mode for displaying the progress, the process proceeds to the key determination of step S149, but when this routine is executed for the first time, it is "OFF", so the process proceeds to step S150. The key that has been shifted and entered is determined (step S150). Numeric keypad 21 with input keys "0" to "9", "to" key 2
7. If the key is a numeral-related key such as the "minute" key 29, the process proceeds to step S160 shown in FIG. "+",
When the operation input key 25 indicates the four arithmetic operations such as "-", "x", "÷", the process proceeds to step S280 shown in FIG. When it is the normal key 38, the process proceeds to step S360 shown in FIG. If it is any other key such as the "approximate" key 35 or the "provisional fraction" key 32, other processing is executed (step S155), and the process returns to step S120 to repeat the processing. As described above, since it is assumed that the key input is the value “1” in step S130, it is determined that the ten key 21 is input, and the process proceeds to step S160.

In step S160, the input key is determined again, and the process branches to the next process. If it is the numeric keypad 21, the process proceeds to step S170, if it is the "to" key 27, the process proceeds to step S180, and if it is the "minute" key, the process proceeds to step S190. Since the value "1" is the numeric keypad 21, the process proceeds to step S170, and it is determined whether the input position flag Fa is an integer, a denominator, or a numerator, and the integer part Xa, the denominator part Xb, and the numerator part Xc are correspondingly determined. Substitute the input value (steps S200 and S2)
10, S220). When the input position flag Fa remains the initial value, it indicates an integer, so the input value "1"
Is assigned to the integer part Xa. When the substitution of the input value "1" is completed, the value "1" is displayed on the right end of the liquid crystal display 12 (see FIG. 10 (1)). After that, the process returns to step S120 and the process is repeated as described above.

Next, the entered key is the "to" key 27.
If so, the input position flag Fa is determined (step S1
80) When the input position flag Fa is the "denominator" and the "numerator", the process returns to step S120 without doing anything, and the process is repeated. In this case, however, the input position flag Fa is set to the "denominator". After changing (step S18
5) Return to step S120 to repeat the process. As a result, it is confirmed that it is a mixed fraction. As shown in (2) of FIG. 10, when the "to" key 27 is input, a horizontal line (bar) 170b and a cursor 170a for prompting the input of the denominator are displayed. Further, in (3) of FIG. 10, the value “8” is input to the position of the denominator by the same processing as in (1) of FIG.

Next, as shown in (4) of FIG. 10, when the "minute" key 29 is pressed, the state of the input position flag Fa is judged (step S190), and the input position flag F is determined.
In this case where a is the "denominator", the input position flag Fa is changed to "numerator" (step S240) and the process returns to step S120 to repeat the process. By this processing, the cursor 170a for prompting the input is displayed at the position of the molecular portion in (4) of FIG. When the input position flag Fa remains the initial value of the integer in the determination of step S190, the value of the integer part Xa is changed to the value of the denominator part Xb so that the value previously input to the integer part Xa as the mixed fraction is set to the value of the denominator part Xb. Part Xb
And the value of the integer part Xa is reset to "0" (step S230). After that, the input position flag Fa is set to "numerator" (step S240) and the process returns to step S120 to repeat the process. Step S19
When the input position flag Fa is "0" and the numerator is 0, the fraction has already been input, and therefore the process is repeated without performing anything and returning to step S120.

Next, as shown in (5) of FIG. 10, when the key input value is "2", the above-mentioned step S170 is performed.
The value "2" is assigned to the numerator Xc by performing the processing up to step S220. Therefore, the value "1 2/8" is displayed in (5) of FIG. When the "reduction" key 35 is input in (6) of FIG. 10, reduction processing is performed in step S155. This reduction processing obtains the greatest common divisor of Xb and Xc by the well-known Euclidean mutual division method,
It is performed by dividing each of Xb and Xc by the obtained greatest common divisor. As a result of the arithmetic processing, Xb is the value “4”, Xc
Is the value "1".

Next, in (7) of FIG. 10, the "-" key 42
Is input, the process proceeds to step S280 of FIG. 9 in the determination of step S150. It is determined whether or not the input key is the four arithmetic operations such as the "-" key 42 (step S2).
85). Here, when the operator has already been input, the calculation up to that point is executed (step S290),
When inputting the operator for the first time, the operation term is as it is (right term)
X is moved to the operand (left term) Y (step S30).
0) That is, the values of the integer part Xa, the denominator part Xb, and the numerator part Xc are moved to the integer part Ya, the denominator part Yb, and the numerator part Yc, respectively. Thereafter, the input position flag Fa is set to "integer" (step S310), the operator of "-" is set (step S320), and "11 / 4-" is set from the left side as shown in (7) of FIG. Is returned to step S120 and displayed, and the same processing is repeated. Furthermore, when the fractional input of the operation term (right term) X is performed by performing the same processing as that described above, the fractional expression "1 1/4 -1 / 1" shown in (8) to (10) of FIG. 6 ”is obtained.

Further, when the "divided" key 38 is input in (11) of FIG. 10, the divided processing in step S155 of FIG. 7 is performed. This division processing is performed in the same manner as the above-mentioned reduction processing by the Euclidean mutual division method, and the denominators (Xb, Y
This is done by finding the greatest common divisor G of b).
That is, (Xc · Yb / G) is substituted for the molecular part Xc, (Yc · Xb / G) is substituted for the molecular part Yc, and X
By substituting (Xb · Yb / G) for b and Xb, the processes are uniformly performed. As a result, the display of (11) in FIG. 10 is obtained. When the “=” key 39 is pressed in (12) of FIG. 10, the process proceeds to step S345 of FIG. 9 and the mode is determined. If it is the learning mode, the progress flag Fc is set to "ON" in step S355, and the process proceeds to the midway progress display mode. Here, since it is the fractional mode, the process proceeds to step S350 to perform the same arithmetic processing as in step S290, and then returns to step S120 to display the calculation result shown in (12) of FIG. In (13) and (14) of FIG. 10, every time the "improper fraction" key 32 is input, the improper fraction is changed to the mixed fraction in step S155.
Alternate conversion from mixed fractions to improper fractions. (1 in FIG.
In 3), (Xa · Xb + Xc) is substituted for Xc, and Xa
By substituting the value “0” into
/ 12 ”is displayed. Also, in (14) of FIG.
The quotient obtained by dividing c by Xb is substituted for Xa, and the remainder is substituted for Xc to display "1 1/12".

Next, the halfway progress display mode in the learning mode will be described. FIG. 11, FIG. 12 and FIG. 13 are flowcharts showing a part related to the midway progress display mode in the fraction calculation routine. 14 and 15 are diagrams showing a display mode in response to a key operation. 14 (2)
0) is the fractional calculation formula “5 entered in the same procedure as in FIG.
/ 6 + 3/10 ”is shown. With the mode selection switch 14 switched to the "learning" mode, (21) in FIG.
9 is input, the progress flag Fc is set to "ON" in step S355 of FIG. 9 described above, and the mode in which the calculation in the middle of step S360 and thereafter is displayed. In the midway progress display mode, the calculation content for executing the next step is determined during the calculation of the fractional calculation formula, and the calculation content is set in the next flag Fd. First, the operator of the above-described fractional calculation formula is determined (step S
360). When the operator is addition / subtraction, the processing from step S370 is performed, when the multiplication / division is performed, the processing from step S530 is performed, and when the operation is already finished and only the right term is reached, the processing proceeds to step S710 and later. .
In step S370, it is determined whether the denominators of the fractions to be added or subtracted are equal, and if they are not equal, it is determined whether the fraction Y of the left term and the fraction X of the right term can each be reduced (steps S380 and S390). . If the reduction is possible, "reduction 1" and "reduction 2" are set in the next flag Fd, and the process returns from step S120 (steps S400 and S410). When neither of them can be reduced, "complete" is set in the next flag Fd, and the process returns from step S120 (step S420). still,
Whether or not divisor can be reduced is determined by whether or not the greatest common divisor according to the Euclidean mutual division method is the value “1”. 14 (2)
In 1), neither can be reduced, so step S370,
When the processing is executed in the order of S380, S390, and S420, and "complete" is set in the next flag Fd, step S1
The display returns to 20 and "Complete" is displayed. Next, as shown in (22) of FIG. 14, since the progress flag Fc is set to “ON” when the “=” key 39 is input, the “=” key 39 is used as the “next step” key 39. It works, performs the processing of steps S147 and 149 described above, and shifts to step S810. In step S810,
The calculation contents set in the next flag Fd are processed. First, it is determined whether or not the calculation content set in the next flag Fd is “end”. If it is “end”, no processing is performed thereafter, and the process returns to step S120. When it is other than "end", the calculation content of the next flag Fd is read (step S82).
0), and after performing various arithmetic processes according to the calculation contents (steps S830 to S930), the process returns to step S360. In the example of (22) of FIG. 14, in step S840, the same processing is performed as in the case of (11) of FIG. 10 described above. Since the denominators of the fractions of both terms have become equal, in the processing of step S370 executed again, step S4
Go to 10. In step S410, when the operator is addition, "calculation" is set in the next flag Fd in step S420, and in subtraction, if the number of the numerator compared in step S430 is larger, the value is "carry". If not, "calculation" is set in the next flag Fd (step S
420, S440) Return to step S120. When "calculate" is set in the next flag Fd, "next" is displayed on the liquid crystal display 12.

Next, in (23) of FIG. 14, steps S810 to S930 are performed in the same processing procedure as (22).
Are sequentially executed to perform addition processing. When you add
The result is stored in the fractions Xa, Xb, and Xc of the right term.
Since the operator is "NOP", step S360 is executed again.
When executing, the process proceeds to step S710. In step S710, the sizes of the denominator part Xb and the numerator part Xc are compared, and if the numerator part Xc is larger or equal, step S7.
In step 20, the "division number" is set in the next flag Fd, and if it is smaller, it is determined in step S730 whether or not it can be reduced. If it can be reduced, it is "divided 2" in step S740, and if it cannot be reduced, "end" in step S750. Is set to the next flag Fd and the process returns to step S120. In the case of (23) in FIG. 14, the process proceeds from step S710 to step S720,
"Fixed number" is set in the next flag Fd and step S1
Return to 20. Similarly, in (24) of FIG. 13, when it is converted into a mixed fraction in step S910, “about 2” is set in the next flag Fd in step S740, and further, in FIG.
In (25) of, about minutes are performed in step S860,
In step S750, "end" is set in the next flag Fd, and the display shown in (25) of FIG.

FIG. 15 shows an example of division of a fractional calculation formula. (30) of FIG. 15 shows the fractional calculation formula “3 1/3 ÷ 4/5” input in the same procedure as the example of FIG. 10. When the “=” key 39 is input at (31) in FIG. 15, the process proceeds to the midway progress display mode by the processing of steps S280, S345, and S355 described above, and it is determined that the operator is “÷” by step S360 described above. The process moves to S530. If the left term Y is a mixed fraction, "improper fraction 1" is set in the next flag Fd (step S540), and if the right term X is a mixed fraction, "improper fraction 2" is set in the next flag Fd ( (Steps S550 and S560), if the operator is division, set "reciprocal" to the next flag Fd (Steps S570 and S580), and if Yb and Yc of the left term Y can be reduced, "reduce 1" Is set to the next flag Fd (steps S590 and S600), and Xb and Xc of the right term X are set.
Is reduced to the next flag Fd (steps S610 and S620), the numerator part Yc of the left term and the denominator part Xb of the right term are reduced to "about". Minute 3 "is set in the next flag Fd (steps S630, S
640), if the denominator part Yb of the left term Y and the numerator part Xc of the right term X can be reduced, "about 4" is set in the next flag Fd (steps S650 and S660), and both are applicable. If not, "calculation" is set in the next flag Fd and the process returns to step S120. In the case of (31) in FIG. 15, "improper fraction 1" is set in step S540. Next Figure 15
In (32), when the left term Y is converted to an improper fraction in step S890, "reciprocal" is set in the next flag Fd in step S580.
Is set. In (33), when the denominator part Xb and the numerator part Xc of the right term X are exchanged and the operator is set to “multiplication” in step S830, the next flag F is set in step S640.
“About 3” is set in d. In (34) of FIG. 15, the processing is reduced in step S870, and "calculation" is set in the next flag Fd in step S730. (3 in FIG.
In 5), when the multiplication is executed in step S930, the "additional number" is set in the next flag Fd in step S720. In (36) of FIG. 15, it is converted into a mixed number in step S910, and "end" is set in the next flag Fd in step S750.
When is set, a series of intermediate progress display processing ends. In addition, in (31), (32), and (33) of FIG. 15, "3 1/3", "4/5", and "10" to be processed are shown.
The portion of "4" and "4" may be displayed by blinking, which makes it easier to understand.

As described above, according to the fractional computer 10 of this embodiment, the fractional calculation process is stepwise displayed as shown in (21) to (25) of FIG. Helps you understand the concept.

[Second Embodiment] Next, a fraction calculator 50 according to a second embodiment will be described. FIG. 16 is a fraction calculator 50
3 is a perspective view showing the external appearance of FIG. In the fraction calculator 10 of the first embodiment, the display of the progress is displayed in order by pressing the "next step" key 39 overlapping the "=" key, but in the present embodiment, this "next step" key 39 is displayed. Instead of "," a "previous step" key 190 and a "next step" key 191 are provided to overlap with the "M-" key and the "M +" key respectively, and by pushing these keys 190, 191, the calculation can be advanced. , Configure to display the calculation in the middle by going back and forth.

FIG. 17 is a block diagram showing the internal structure of the data memory 154 used in the second embodiment. The data memory 154 has stacks 180, 181, and 182 for sequentially storing the calculation contents in the middle.
Here, the stacks 180, 181, and 182 are X in the right term.
a, Xb, Xc set, Ya, Yb, Yc set in the left section, and the contents of the next step Fd are first-in first-out (FIL
O) format. It should be noted that the reference numerals in the drawings which are not particularly different from those in the first embodiment are designated by the same reference numerals.

18 and 19 are flow charts showing the fraction calculation routine of the second embodiment. FIG. 19 is a diagram showing a display mode in response to a key operation. In FIG. 20, (4
0) and (41) are (20) of FIG. 14 of the first embodiment,
It is displayed in the same processing procedure as (21). Next, FIG.
When the "next step" key 191 is input at (42) of, the determination shifts to step S148 of FIG. In step S148, the entered key is judged, and when the "previous step" key 190 and the "next step" key 191 are pressed, those judgments are further judged in step S805.
And press any other key, step S
Return to 120. In (42) of FIG. 20, since the "next step" key 191 has been input, the process moves to step S805. When the "previous step" key 190 is pressed in step S805, the "next step" key 1 is displayed in step S807.
When 91 is pressed, the process proceeds to step S810. In step S810, since the next flag Fd is "successful", the process proceeds to step S815. In step S815, the current right terms Xa (= 0), Xb (= 6), and Xc (= 5) are placed in the stack 180, and the left terms Ya (= 0), Yb (= 10),
Yc (= 3) is pushed down to the stack 181, and the next flag Fd (= “through”) is pushed down to the stack 182. From step S820 onward, the total calculation is performed by the same processing as in the first embodiment. Next, in (43) of FIG. 20, similarly, "0", "30", "25", and stack 1 are added to the stack 180.
“0”, “30”, “9” are pushed to 81, and “calculation” is pushed down to the stack 182. Next, (4 in FIG.
When the "previous step" key 190 is input in step 4), the process proceeds from step S805 to step S807, and in step S807, the stack 180 is set in (43) of FIG.
The values stored in the stack 181 and the stack 182 are respectively popped up, and the process returns to the display process of step S120. The step (44) in FIG. 20 has returned to the calculation state one step before similarly to the step (42) in FIG. Continued in (20) (4
The process after 5) is the same as the process after (23) in FIG.

As described above, in the second embodiment, the fraction calculator 50 stores the state of each calculation stage in the stack 18
Since 0, 181, and 182 have been allocated in the data memory 154, fractional calculations can be displayed retroactively by popping values from the stacks 180, 181, and 182 by pressing the "previous step" key 190.

[Third Embodiment] A fractional computer according to the third embodiment will be described below. 21 and 22 show a flowchart of the fraction calculation routine of the third embodiment.
It is a modification of FIGS. 11 and 13 of the embodiment. FIG. 23 is a diagram showing a display mode in response to a key operation. Portions which are the same as those in the first embodiment and which do not require particular explanation are designated by the same reference numerals. In the third embodiment, the next flag F is set while waiting for the key input of the "next step" key 39.
After displaying "Next" key 39 without displaying the contents of d and pressing the "Next step" key 39, the next flag Fd showing the contents of processing is blinked for a certain period of time, and then the contents of the next flag Fd are processed. And display the result.

The parts of the flowcharts of FIGS. 21 and 22 different from the first embodiment will be described below.
In step S149 of the first embodiment, when the "next step" key 39 is pressed, the processing of the content of the next flag Fd shown in FIG. 13 is executed, the next processing is determined, and the content of the next processing of the next flag Fd is determined. 11 was set (steps S360 to S750 in FIG. 11), but in the third embodiment, the order of this processing is changed and the next processing shown in FIG. 21 is determined first and the processing content is set in the next flag Fd. Then, after that, the processing of the content of the next flag Fd shown in FIG. 22 is executed. Further, before executing the processing of each next flag Fd, the content or operator of the next flag Fd processed in step S950 is displayed in blinking. (50) of FIG. 23 shows the fraction calculation formula displayed by the same input processing as (20) of FIG. 14 of the first embodiment. In FIG. 23 (51), the “=” key 39
Is entered, the mode is changed to the intermediate display mode, and the process to be executed next is determined in the flowchart of the fraction calculation routine of FIG. When the next flag Fd is "through", "through" is displayed in a blinking manner in step S950 in FIG. 22, and then the through process is executed in step S840, and the process returns to step S120 and returns to (52) in FIG. Will be displayed.
Similarly, in (53), (55), and (57) of FIG. 23, after inputting the "next step" key 39, the respective processes of "+", "consolidated fraction", and "approximately" are blinked. In FIG. 23, (5
The calculation results of 4), (56), and (58) are displayed.

As described above, in the present embodiment, only the display of "Next" is displayed while waiting for the input of the "Next step" key 39, so that the operator can think about what to do next. By inputting the "next step" key 39 and confirming whether or not the idea was correct, the content to be processed next can be considered.

Various modifications can be made to the first to third embodiments described above without departing from the scope of the present invention. For example, the values input to the denominator portion and the numerator portion may be manually input, or a random number generator may be provided and the random numbers generated from the random number generator may be input. The driving method of the liquid crystal display 12 is not limited to the simple matrix driving method, but may be the active matrix driving method. Further, not only the liquid crystal display but also various ones such as a CRT display and a plasma display can be used.

[0032]

As described above, since the intermediate result of the fractional calculation is displayed on the display means every time the next process is designated in the fractional calculation, the calculation process of the fractional calculation can be easily shown.

[Brief description of drawings]

FIG. 1 is a perspective view showing an appearance of a fractional calculator 10 according to a first embodiment.

FIG. 2 is a block diagram showing a configuration of a control circuit 20.

FIG. 3 is an explanatory diagram showing an internal configuration of a data memory 54.

FIG. 4 is a front view showing the configuration of all display segments 12a of the liquid crystal display 12.

FIG. 5 is a connection diagram showing a common electrode of all display segments 12a.

FIG. 6 is a connection diagram showing segment electrodes of all display segments 12a.

FIG. 7 is a flowchart showing a fraction calculation routine of the first embodiment.

8 is a flowchart showing a fraction calculation routine following FIG.

9 is a flowchart showing a fraction calculation routine following FIG. 7. FIG.

FIG. 10 is an explanatory diagram showing a display mode corresponding to a key operation.

11 is a flowchart showing a fraction calculation routine following FIG.

12 is a flowchart showing a fraction calculation routine following FIG.

FIG. 13 is a flowchart showing a fraction calculation routine following FIG.

FIG. 14 is an explanatory diagram showing a display mode corresponding to a key operation.

FIG. 15 is an explanatory diagram showing a display mode corresponding to a key operation.

FIG. 16 is a perspective view showing the external appearance of the fraction calculator 50 according to the second embodiment.

FIG. 17 is an explanatory diagram showing an internal configuration of a data memory 154 of the second embodiment.

FIG. 18 is a flowchart showing a fraction calculation routine of the second embodiment.

FIG. 19 is a flowchart showing a fraction calculation routine following FIG.

FIG. 20 is an explanatory diagram showing a display mode corresponding to a key operation.

FIG. 21 is a flow chart showing a fraction calculation routine of the third embodiment.

22 is a flowchart showing a fraction calculation routine following FIG. 20. FIG.

FIG. 23 is an explanatory diagram showing a display mode corresponding to a key operation.

[Explanation of symbols]

 10 ... Fraction calculator 12 ... Liquid crystal display 14 ... Mode switch 17 ... Fraction designation key 21 ... Numeric keypad

Claims (2)

[Claims] 1. A fraction setting means for inputting a value to a denominator and a numerator to set a plurality of fractions, and a formula setting means for setting a fraction calculation formula for a plurality of fractions set by the fraction setting means, In a fractional calculator provided with a calculation means for calculating the fractional calculation formula set by the calculation formula setting means, and a display means for displaying the fractional calculation formula, wherein the calculation means is a step of advancing the fractional calculation formula. A fractional calculator comprising: a calculation stopping means for stopping calculation; and the display means including a progress step display means for displaying the calculation of the progress step stopped by the calculation stopping means. 2. The advancing step storage means for sequentially storing the advancing step calculation each time the advancing step is stopped by the advancing step calculation means, and the advancing step calculation sequentially stored in the advancing step storage means. 2. The fraction calculator according to claim 1, further comprising: a retrograde designating means for performing a retrograde operation, wherein the display means includes a retrograde display means for displaying the calculation of the progressing stage which is reversed by the retrograde designating means.