JPS5853376B2 - Calculation method for calculating discount premium - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an arithmetic method for performing discount/surcharge calculations using a digital arithmetic device such as an electronic desktop calculator.

Discount or premium calculation is to calculate the value of b% subtraction or b% increase from numerical value a, and such calculations, which are often required in office calculations, have traditionally been performed using, for example, a calculator with a percentage key. It was possible to implement it.

In general, a digital arithmetic device is equipped with a numeric key for entering arithmetic data, an arithmetic key for instructing some kind of processing on the arithmetic data, and a decimal point key for indicating the decimal point position of the data.

Arithmetic keys include addition key, subtraction key, multiplication key, division key, and equal key.
A normal calculator has a calculator that allows you to perform addition, subtraction, multiplication, division, and percentage calculations.

With the recent development of LSI (large-scale integrated circuits), digital arithmetic devices have become significantly smaller, and the arithmetic circuits in calculators and the like are now constructed from a single LSI, and even more advanced arithmetic functions can be added. It is possible.

When adding new arithmetic functions, it is necessary to make key operations as simple as possible and at the same time to make maximum use of the already existing arithmetic functions to prevent an increase in circuit area.

BACKGROUND ART Conventionally, there is an arithmetic method based on a flowchart shown in FIG. 1 as an example of premium calculation or discount calculation.

This flowchart shows the operand a (hereinafter abbreviated as "ma")
This shows the processing of the key % or the key RO in the state after the key operations Nagi OX and I have already been performed between

Step 1 is the start step when you press the key or %. In this state, the operand a is the contents of the operand register Regi (Regi), and the operand a is the contents of the operation register Reg2 (Reg2). Each is memorized.

Also, the state in which the prisoner key is pressed is also stored.

(Multiplication instruction (→ is memorized) If the ta key or day key is pressed now, the addition instruction (1) will be used as the calculation instruction.
Alternatively, a subtraction instruction (-) is stored.

Here, the key operations for Oka, Ku, and (6) have been completed, so if you press the % key next, it will proceed from step 2 to step 3, and since ) is memorized in the multiplication instruction, step 4
Proceed to.

In this step 4, the decimal point position data [PREG2] of the operation number stored in the operation register Reg2 is
2" is added and the decimal point is advanced by two places.

By this process, the calculation number is multiplied by 1/100.

Next, proceed to step 7, store the product of the contents of register Regl and the contents of register Reg2 in register Reg2,
Proceed to end step 12.

Thus-b Arithmetic register Reg2 contains □, that is, b%00 of a. This means that a value corresponding to .

Note that steps 7, 9, and 11 in the figure are conventional multiplication, addition, and subtraction steps, respectively.

Next, when using the conventional device to perform discount and premium calculations, i.e., to calculate b% off of a or b% increase from a, key - b - is operated in the order of fig, ku, (8), %. , and then press the keys 日, 日 00, 田, 日 and a -a-b.
Find a-b or a+.

In other words, 100 100 Now, a is stored in register b Regl and □00 is stored in register Reg2 by key operations such as ``ai'', ``koku'', ``old'', and %. c) Or, if you memorize the addition command and then press the LOCKey, as is clear from Figure 1, the subtraction command (for →, step 1 → 2 → 5 → 6 → 8 → 10 → 11 → 1
2, and a- is found in the arithmetic register -b Reg2.

Also, for addition instruction 00 (+), step 1 → 2 → 5 → 6 → 8 → 9 → a
-b.

Proceed to 12 and write a+□ or 00 to calculation register Reg2. Desired.

It should be noted that all 42 ports in the figure are paths taken when key operations other than those described above are performed, and their explanation will be omitted here.

The above is a conventional method for performing discount and premium calculations, but this calculation method requires two numeric operations and four calculation key operations.

In other words, the discount calculation requires the operations zoku, ■, %, 日, ro, and the premium calculation requires the operations 输, fig, ■, %, 田, 日, all of which require complicated key operations. Compared to other operations such as addition, subtraction, multiplication, and division, this method has the disadvantage that it is much more likely to cause errors in key operations.

This invention has been made in view of the above points, and when adding a discount/surcharge calculation function to a digital arithmetic device such as an electronic desktop calculator, it can be made as simple as key operations for addition, subtraction, multiplication, and division. The object of the present invention is to provide an arithmetic method that reduces the possibility of key operation errors occurring in conventional methods.

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 3 is a system diagram of essential parts necessary for implementing the present invention, and FIG. 4 is a schematic explanatory diagram of the present invention using these systems.

In FIG. 3, 13 is a keyboard having a numeric keypad, an addition key, a subtraction key, and a percent key; 14 is an arithmetic circuit; 15 is a memory for storing operands; 16 is a memory for storing operands; 1T is a first and second - The third judgment means, 18 is a control ROM for executing a multiplication routine, a division routine, an addition routine, a subtraction routine, and a numeric routine; 19 is a display circuit;

As shown in Figure 4, the first, second, and third judgment means shown in 1T are used to judge ×, ÷, 10, -, and also to check whether the percent key has been pressed or not, and to check whether the percent key has been pressed or not. In numbers, it is determined whether + or - is pressed.
Furthermore, it is determined whether the +/- keys were operated in the previous key operation.

FIG. 2 is a flowchart of the same embodiment, in which the operand a is stored in the operand register Regl and the operand a is stored in the operation register Reg2 by performing key operations such as ``Figure'', ``ku'' (or 田 or 日), and ``old''. and the calculation instruction (×
) (or (1) or (-)) is stored. The process flow when the % key or the Lo key is pressed is shown.

In the method of this invention, the key operations for discount calculation are ``field'', ``day'', ``old'', and %, and data processing by these key operations is as follows.

If you press the iron key after operating the prison, day, and (6) keys,
The process proceeds from the start step 21 in FIG. 2 to step 22, and when the condition that it is a % key is established, the process proceeds to step 23.

Next, in step 23, since the arithmetic instruction is (rather than ladle), the process proceeds to step 24, and from there, the process proceeds to step 25.

In step 25, "2" is added to the decimal point position data of the operation number stored in the operation register Reg2, the decimal point is advanced by two digits, and the operation number is set to b/xoo.

Next, proceed to step 28 and register Regl and register R.
Store the product of the contents with eg2 in register Reg2.

Thus, -b Arithmetic register Reg2 is or operand register 00 Then a will be stored in Regl.

Next, the process proceeds to step 29, and since the subtraction instruction is stored, the condition here is met, and the process proceeds to step 30.

Since the condition is not satisfied in step 30, the process proceeds to step 32, where the condition that subtraction, substitution, and then is satisfied is satisfied, and the process proceeds to step 33.

In step 33, the result of subtracting the data □ stored in the calculation register Reg2 from the data a stored in the operand register Reg1 is stored in Reg2 as 00.

In other words, at this point, register Reg2 has a8°”, LL
iaO'l)% Bow 1.

Find the value 91.700 Proceed to step 34.

On the other hand, the key operations for calculating the premium are 0, 0, 0, and %, which will be similarly explained with reference to the flowchart shown in FIG.

First, after operating the same, 田, and same keys, press the % key. Steps 21 → 22 → 23 → 24 → 25 → 28 → 29 →
30 and advance -b, □ is found in the arithmetic register Reg2.

00 At this time, the fact that a is stored in the operand register Reg1 is the same as in the case of discount calculation.

Next, in step 30, since the addition instruction (a) is stored, the condition is met, and the process advances to step 31, where addition is performed.

In other words, data a and -b of register Reg1 The data in register Reg2 is added to 00. The result is stored in register Reg2.

When a+ is found in register b Reg 2, end step 0
The process advances to 034 and the calculation of increasing a by b% is completed.

Incidentally, C and C in the figure are both routes when key operations other than those described above are performed, and their explanation will be omitted here.

As is clear from the above explanation, according to the method of the present invention, the discount and premium calculations are performed in the following manner:
It can be performed with four key operations (Koshida, Aim %) (one time each for a and b), and calculations can be performed with key operations that are as simple as conventional key operations for addition, subtraction, multiplication, and division. , the possibility of errors due to key operation errors is significantly reduced, and the operability of calculators and the like is improved.

Furthermore, as can be understood by comparing FIG. 1 and FIG. 2, the number of calculation steps is increased by only two steps 24, 290, and the logic circuit of the conventional method can be used to a large extent.

It should be noted that the above-described embodiment is an example of the method of the present invention realized according to the flowchart shown in FIG. 2, and it goes without saying that various other embodiments are actually possible.

For example, the operation of shifting the decimal point position data of register Reg2 by two digits, which is performed in step 25 of FIG. 2, can be performed after the multiplication in step 28 has been performed, and the result will be the same.

Furthermore, for example, the judgment conditions for steps 24 and 29 in FIG.
Other judgment conditions may be set as long as it can be confirmed that the series of operations A and B have been performed.

As detailed above, according to the present invention, the key operation is extremely simple, and the circuit area is reduced by making maximum use of the already existing arithmetic functions, thereby reducing the possibility of key operation errors. It can provide calculation methods.

[Brief explanation of drawings]

FIG. 1 is a flowchart showing an example of a conventional discount/surcharge calculation, FIG. 2 is a flowchart showing an example of the method of the present invention, and FIG. 3 is a system diagram of essential parts necessary for explaining the present invention. FIG. 4 is a schematic explanatory diagram for explaining the first, second, and third determining means.

Claims (1)

[Scope of Claims] 1. A keyboard having a numeric key, an addition/subtraction key, and a percent key, a memory for storing operands, a memory for storing arithmetic numbers, first, second, and third determination means, and an operation Circuits, multiplication routines, division routines, addition routines,
Control ROM that executes subtraction routines and number routines
The operand a is placed in the first position, the addition or subtraction key is operated in the second position, the operand is placed in the third position, and the percent key is pressed in the fourth position. By manipulating a-b a-b, a+ or a −□ becomes 100
100 Use the calculation method to perform numerical calculations, and use the above a + 8° 5
Execute the operation a°5 at the first position 100
100 The operand a is stored in the operand storage memory, the addition, subtraction, multiplication, and division are determined by the second key operation using the first determination means, and the operand a is determined by the third digit. It is stored in the memory for storing arithmetic numbers, and the second determining means determines whether the fourth key is a percent key, and if this key is a percent key, the previously operated arithmetic key is The second determining means determines whether or not the key is an addition/subtraction key, and if the key is an addition/subtraction key, the decimal point position of the operand is advanced by two digits to the upper digits and stored in the memory for storing the operands. The arithmetic circuit calculates the product with the pre-stored operand a and stores it again in the arithmetic number storage memory, and the third determining means determines whether the key operated before operating the percent key is the addition key. , and calculate the sum of the operand a previously stored in the operand storage memory and the product obtained above, and calculate the operand by determining that the operated key is the subtraction key. An arithmetic method for discount premium calculation, characterized in that the difference is obtained by subtracting the above-determined product from the number a, and this sum or difference is stored again in a memory for storing arithmetic numbers.