JPH06214955A - Financial computer - Google Patents

Abstract

(57) [Summary] [Purpose] The desired calculation can be performed by simply inputting data without setting the calculation mode in advance, and the calculation formula can be changed even in the middle. [Structure] Multiple financial formulas are stored in memory in advance, and for the variables of the principal, the total of interest and the amount paid per payment, which of the compound interest rate, the fund and the loan is used depending on which variable is input. It is determined whether or not there is a calculation, and arithmetic processing is executed according to the calculation formula. First, if the payment amount data per payment is not input, it is determined that the compound interest is calculated, the compound interest calculation is executed, and the calculation result is displayed on the display unit. Also,
When the payment amount data is input but the total interest and interest is not input, the term-end payment or the beginning-term loan calculation is executed, and the calculation result is displayed on the display unit. When the payment amount data and the total interest and interest amount are input, the period end payment or the beginning payment is calculated and the calculation result is displayed on the display unit.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a financial computer for performing financial calculations such as compound interest calculation, loan calculation, and reserve calculation.

[0002]

2. Description of the Related Art Conventionally, some small electronic calculators are provided with financial calculation functions such as compound interest calculation, loan calculation, and reserve calculation. This type of conventional financial calculator is configured to preset the mode of each calculation.

[0003]

Since the above-mentioned conventional financial calculator is configured to preset the mode of each calculation, the compound interest is calculated prior to the calculation, and the loan is calculated for the loan calculation. The mode setting operation had to be performed, which was troublesome. Moreover, since the calculation mode must be set in advance as described above, the calculation formula could not be changed while data was being input.

The present invention has been made in view of the above circumstances, and a desired calculation can be performed only by inputting data without setting a calculation mode in advance, and the calculation formula can be changed midway. The purpose is to provide a financial calculator that can.

[0005]

According to the present invention, in a financial computer for performing financial calculations such as compound interest calculation, loan calculation, and reserve calculation, a calculation formula storage means for storing a plurality of financial calculation formulas in advance, and Payment amount data storage means for storing the payment amount data, a total interest and interest data storage means for storing the total interest and interest data, and a first determination device for determining whether or not the payment amount data is stored in the payment amount data storage means. A discriminating means, a second discriminating means for discriminating whether or not the principal and interest total data is stored in the principal and interest total data storage means, and it is discriminated that the payment amount data is not stored by the first discriminating means. When it is done, execute the compound interest calculation,
The loan calculation is executed when it is determined by the first determining means that the payment amount data is stored and when it is determined by the second determining means that the principal and interest total data is not stored. When the first determining means determines that the payment amount data is stored and the second determining means determines that the total interest and interest data is stored, the reserve calculation is executed. And a display means for displaying a calculation result by the financial calculation means.

[0006]

When performing a financial calculation, the principal, the total interest and the amount of payment per payment are input according to the type of calculation. The financial calculator determines which of the formulas of compound interest, fund, and loan is used for the variables of the principal, the total interest and interest, and the amount of payment per payment, and calculates according to the formula. To execute.

That is, if the payment amount data per payment is not input, it is determined that the compound interest is calculated, the compound interest calculation is executed, and the calculation result is displayed on the display unit. Also, if payment amount data is entered but total interest and interest data is not entered, it is determined that the loan is calculated, and the loan calculation of the term-end payment or the beginning-of-year payment is executed according to the input instruction, and the calculation result is displayed on the display unit. To display. If the payment amount data and the total interest and interest data are input, it is determined that the calculation is for reserves, and the reserve calculation for the term end payment or the beginning payment is executed according to the input instruction, and the calculation result is displayed. To be displayed on the department. By simply inputting the data of the three items as described above, a calculation formula for the data is derived, and a desired financial calculation is performed based on the formula.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The following is a detailed description of the case where the present invention is applied to an electronic wrist watch with a calculation function, with reference to the drawings. First, the external structure will be described with reference to FIG. In the figure, reference numeral 1 is a wristwatch case. The wristwatch case 1 is provided with a display portion 2 and a keyboard 3 on the front surface, and a shift key 4, an ANS key 5, an ENT key 6, and a mode key 9 on the side portion. The keyboard 3 is provided with, for example, 16 keys, and the numerical keys and the function keys for the four arithmetic operations have the input function of the data for financial calculation, that is, the three-function function. The function of each key is shifted by the shift key 4. That is, the "0" key has "P
(Principal amount in payment amount), "I" (interest in payment amount) for the "." Key, "Bal (remaining amount of principal amount)" for the "=" key, and "for the 1" key. N (number of periods), "2" key for "i% (interest rate)", "3" key for "Acc (total interest payment)", "4" key for "PMT (payment per payment)""Amount)","5" key to "PV (principal)",
"6" key is "FV (total interest)", "7" key is "CST (stock price)", "8" key is "SEL" (selling price), "9" key is "net profit margin" ) ”Function.

When the shift mode "1" is designated by the shift key 4, the input mode of the numerical keys and the function keys for the four arithmetic operations is selected, and when the shift mode "2" is designated, the function key relating to the financial calculation is designated. Enter the input mode. When the shift mode "3" is designated, key input such as "In (logarithmic calculation)" provided on the "0" key and "e (exponential calculation)" provided on the "." Key It becomes a mode. Also,
The mode key 9 switches and designates three modes of "clock", "alarm", and "financial calculation".

On the other hand, the display section 2 is provided with an 8-digit time / data display section 7 and a 4-digit date display section 8 in two stages as shown in FIG. The time / data display section 7 is
In the clock mode, the day of the week and hours, minutes, and seconds are displayed, and in the financial calculation mode, numerical data such as input data and calculation results are displayed. Further, in the display unit 2, below the time / data display unit 7, "INT (compound interest calculation)", "LOAN (loan calculation)", "SF (fund calculation)", "BGN (beginning payment)". , END (end-of-term payment) display electrodes are provided. Further, on the upper side of the time / data display section 7, "ENT
(Input) ”,“ ANS (answer) ”display electrodes are provided, and“ AM (am) ”,“ PM (pm) ”and alarm mark display electrodes are provided.

Next, the structure of the electronic circuit provided in the wristwatch case 1 will be described with reference to FIG. In the figure, a ROM 11 controls a whole system and executes a flow chart described later.
That is, it is a fixed memory containing a microprogram and data for executing compound interest calculation, loan calculation, and reserve calculation according to a predetermined calculation formula. ROM address control unit 1
Reference numeral 2 is a control block that specifies the address of the ROM 11 and defines the flow of the program. The control block 2 includes an output NA that specifies the next address of the ROM 11 and an arithmetic circuit (A
The output of the LU) 13 and the output from the frequency divider circuit described later are input. Reference numeral 14 denotes a RAM, which is a memory for outputting the data at the addresses designated by the address data outputs SU, SL and FU, FL of the ROM 11, and for inputting and storing the result data processed and processed by the arithmetic circuit 13. . Details of the RAM 14 will be described later.

An instruction decoder 15 is a block which decodes the instruction output Ins of the ROM 11 and sends a control signal to each block. The arithmetic circuit 13 described above performs an arithmetic logic operation with S and F as inputs, and writes the output to the address of the RAM 14 designated by the outputs FU and FL of the ROM 11. A latch circuit 16 temporarily stores the contents of the address of the RAM 14 designated by the outputs SU and SL of the ROM 11 and sends it to another input S in synchronization with the input F of the arithmetic circuit 13.

Reference numeral 18 denotes an oscillator, which supplies a clock signal of, for example, 32768 Hz to a timing pulse generating circuit 19 and a frequency dividing circuit 20. Timing pulse generation circuit 19
Outputs a timing signal for controlling each block in time series based on the clock signal. Frequency divider 2
Reference numeral 0 is a counter that divides the output from the oscillator 18 to generate a clock signal of a constant cycle, and the clock signal is used for clock processing and the like.

Further, reference numeral 21 is a key input section comprising the keyboard 3 and other keys, which outputs a key input signal in response to a key operation. Reference numeral 2 denotes the above-mentioned display unit which displays input data and processed data via the display buffer 22. The buzzer 23 is a block that generates an alarm sound or the like based on the data from the bus line.
Bus control gates A1, A2, B1, B2, C1
~ C4, D1 and D2 are instruction decoders 1
The gate opens and closes based on the output signal of 5 and controls the data flow of each bus line.

However, the RAM 14 is provided with areas such as a display register, a time storage unit, an alarm time storage unit, a register arithmetic register, a mode flag M, and a key flag unit as shown in detail in FIG. There is. The mode flag M is set to "0" in the clock mode, "1" in the alarm mode, and "2" in the financial calculation mode. The key flag section temporarily stores a key flag for the function key. R above
The AM 14 further stores an area for storing data necessary for financial calculation, that is, the principal PV, the payment amount PMT, the net profit margin MAR, the interest rate i%, the number of periods N, the payment date discrimination flag Fa at the beginning or end of the period, and the principal interest. Storage areas for total FV, purchase price CST, selling price SEL, etc. are provided.

Next, the operation of the above embodiment will be described. Figure 5
3 is a flow chart showing a schematic operation of the whole. Normally, it is in the HALT state as shown in step A1, and stands by until the clock signal is output from the frequency dividing circuit 20 or a key input is given from the key input unit 21. In this HALT state, when the clock signal is output from the frequency dividing circuit 20, the process proceeds to step A2 and the clock processing is executed. That is, in FIG. 3, the frequency dividing circuit 2
0 divides the output signal of the oscillator 18 to generate a clock signal of a constant cycle, and outputs it to the ROM address controller 12. As a result, the timekeeping process is executed and the current time is written in the time storage unit in the RAM 14.

When the time counting process is completed, the calculation process relating to the financial calculation shown in step A3 is executed, and then the process proceeds to step A4. In this case, if no data relating to financial calculation is input, the process proceeds to step A4 and the display process is performed according to the designated mode at that time. For example, if the clock mode is specified, RAM1
4, the contents of the time storage unit are read to the display register and displayed on the time / data display unit 7, and if the financial calculation mode is specified, the contents of the calculation register are read to the display register and displayed on the time / data display unit 7. To do. Then step A
It returns to 1 and enters the HALT state. In addition, when a key input for performing financial calculation is given from the key input unit 21 in this HALT state, the flow proceeds to step A5 to perform the key fetch processing, and then returns to step A1. Then, in step A3, an arithmetic processing relating to financial calculation, which will be described in detail later, is executed based on the key input.

However, the above-mentioned financial calculation means two of the three variables PV (principal), FV (total principal and interest), PMT (payment amount per time), N (number of periods), and i%. For a total of 4 variables of 2 variables of (interest rate), there are 3 calculations of deriving an unknown 1 variable from 3 known variables: (1) compound interest calculation, (2) funded calculation, (3) loan calculation.

(1) In compound interest calculation, PV (principal),
There are four possible variables: FV (total principal and interest), N (number of periods), and i% (interest rate). (2) FV (total principal and interest), PMT
(Payment amount per time), N (number of periods), i% (interest rate)
4 variables are considered.

(3) In the loan calculation, PV (borrowing amount), PMT (payment amount per time), N (number of periods),
There are four possible variables, i% (interest rate). The following Table 1 shows the relations between the above-mentioned calculations of compound interest, reserves and loans and variables.

[0021]

[Table 1]

However, in the step A3, the PV, FV, P
With respect to the variable of MT, it is determined which of the formulas of compound interest, accumulation and loan is used depending on which variable is input, and the arithmetic processing is executed according to the formula. To perform the above financial calculation, the user specifies the financial mode with the mode key 9, and then inputs three sets of item data by operating the shift key 4 and the keyboard 3 in step B1 of FIG. The input data at this time is shown in FIG.
It is written in the corresponding area in the RAM 14 shown in. Then, in step B2, the ANS key is operated and the output item is designated. In this case, if payment is made at the end of the period, the ANS key is operated once, and if payment is made at the beginning of the period, the ANS key is operated twice.

By operating the ANS key, the determination flag Fa is set according to the flowchart of FIG. 7. If the payment is at the end of the period, the flag Fa is set to "1", and if the payment at the beginning of the period is set to "2". To be done. That is, when the ANS key is operated, it is determined in step C1 whether the flag Fa is "0", that is, whether it is the first operation of the ANS key. If "0", the process proceeds to step C2. Set "1" to the flag Fa.

If it is determined in step C1 that the flag Fa is not "0", the flow advances to step C3 to determine whether the flag Fa is "1", that is, ANS.
Determine whether it is the second key operation, and use the flag F
If a is "1", proceed to step C4 and flag Fa
Set "2" to. If it is determined in step C3 that the flag Fa is not "1", it means that the flag Fa is "2", that is, the ANS key has been operated three times (error operation). Then, "0" is written in the flag Fa so that the calculation process is not executed. With the above, the processing for the ANS key is completed. When the ANS key is operated once, "1" is set to the flag Fa, and when the ANS key is operated twice, "2" is set to the flag Fa. .

Then, in step B1 in FIG.
When the key input operation of B2 is completed, the process proceeds to step B3, and it is determined whether or not the PMT (payment amount per payment) is keyed. If not, it is determined that compound interest calculation is performed, and step B4 In step B2, the compound interest calculation process is executed based on the output item designated in step B2. When calculating the number of periods N in compound interest calculation, for example, the necessary data is PV, FV, i%, and the calculation formula is

[0026]

[Equation 1] Is. The compound interest calculation in step B4 above is done in the ROM of FIG.
According to the microprogram stored in 11, the RA
It is executed based on the stored data (item data) of M14. Further, the above-described arithmetic processing is performed by using the numerical arithmetic register, arithmetic register, etc. in the RAM 14, and the arithmetic result is set in the arithmetic register. When the above arithmetic processing is completed, the process proceeds from step B4 to step B5 and the above arithmetic result is transferred from the RAM 14 to the display buffer 2
2 and display it on the display unit 2. At this time, the display unit 2 also displays the letters “INT” indicating that the calculation is compound interest calculation.

In step B3, "PM
If it is determined that "T" has been input, step B
Proceed to step 6 and judge whether or not "FV" is input. If "FV" is not entered, the loan is calculated, and therefore, at steps B7 and B8, it is determined by the flag Fa whether it is the term-end payment or the term-end payment. First, step B
At 7, it is determined whether the flag Fa is "1",
If the value is "1", the payment is made at the end of the period, so the process proceeds to step B9, and the calculation of the payment at the end of the period is executed based on the output item designated at step B2. Loan calculation When calculating the number of periods N in term payment, necessary data are “PV (borrowing amount)”, “PMT (payment amount)”, “i% (interest rate)”, and the calculation formula is

[0028]

[Equation 2] Is.

In step B9, loan calculation is executed according to the above equation to obtain the number N of periods. Also, step B
If it is judged that the flag Fa is not "1" in 7,
In step B8, it is determined whether or not the flag Fa is "2". If it is "2", the payment is made at the beginning of the period. Loan calculation At the beginning of payment, the calculation formula for obtaining the number of periods N is

[0030]

[Equation 3] Is.

When the loan calculation process of steps B9 and B10 is completed, the flag Fa is set to "0" in step B11, and then the process proceeds to step B5. If it is determined in step B8 that the flag Fa is not "2", it means that the flag Fa is "0", and therefore the loan calculation process is not performed and the process proceeds to step B5 through step B11. In step B5, the loan calculation result is output to the display buffer 22 and displayed on the display unit 2 as described above. At this time, the display unit 2 displays “LOAN” indicating that the calculation is a loan calculation, “END” indicating the end of term payment or “BG” indicating the model payment.
The letter "N" is displayed.

If it is determined in step B6 that "FV (total principal and interest)" has been input, it is a funded calculation, and steps B12 and B13 result in steps B7,
As in the case of B8, it is determined whether the payment is at the end of the period or the beginning of the period. If the payment is at the end of the period, the reserve calculation is executed in step B14, and if it is the beginning of the period, the reserve calculation is executed in step B15. In this funded calculation, for example, when the number of periods N is obtained, the necessary data is "FV (total interest)",
"PMT (reserve amount per time)" and "i% (interest rate)"

[0033]

[Equation 4] And the formula for the beginning payment is

[0034]

[Equation 5] Is.

When the reserve calculation process of steps B14 and B15 is completed, the flag Fa is set to "0" in step B11.
After this, proceed to Step B5. In addition, the above step B
If it is determined that the flag Fa is neither "1" nor "2" in 12, B13, that is, if it is "0", the calculation process of steps B14, B15 is not performed, and the process proceeds directly to step B11. Go to B5. In step B5, the result obtained by the calculation processing in steps B14 and B15 is output to the display buffer 22 and displayed on the display unit 2.
At this time, the display unit 2 displays the letters "SF" indicating that the calculation is a reserve calculation, and the letters "END" indicating the term-end payment or "BGN" indicating the model payment.

In the above description, the formula for obtaining the period "N" is shown in any of the compound interest calculation, the loan calculation, and the reserve calculation. However, the above formula is modified even when other items are calculated. Therefore, it can be obtained in the same manner.

Next, a specific example of key operation and display example at the time of the above financial calculation will be described. FIG. 8 shows a specific example in the case of performing compound interest calculation. Now, for example, "principal 5
What is the total amount of principal and interest after 7 years if compounded annually at an annual interest rate of 6% for 0,000 yen? ", The number of years (N)" is input by first operating the keys "7", "ENT" and "N". When inputting "N", the mode is switched by the shift key 4 and the input operation of "N" is performed. The age data is stored in a predetermined area in the RAM 14 and displayed on the display unit 2.

Next, the key operation of "6", "ENT" and "i%" is performed to input the "interest rate". By this input operation, the interest rate "6" is displayed on the display unit 2 instead of the above-mentioned number of years "7". Next, "500000", "ENT", "PV"
Enter the "principal money" by performing the key operation of. By this input operation, “500000” is displayed on the display unit 2. Then, after inputting the above-mentioned three sets of item data, the "ANS" key for instructing output is operated, and then the "FV" key is operated to specify the output item "total interest". By the above key operation, the process is executed according to the flowchart of FIG. In this case, since "PMT (payment amount per time)" has not been input, the determination result in step B3 is NO.
Then, the process proceeds to step B4 and the compound interest calculation is executed.

Then, the calculation result "751815.1
The "295" circle is read from the RAM 14 to the display buffer 22 in step B5 and displayed on the display unit 2 as shown in FIG. In this case, "INT" indicating that the compound interest is calculated is displayed on the display unit 2 together with the calculation result.

FIG. 9 shows a specific key operation and display example when performing loan calculation. For example, if you want to calculate how much you can borrow for a 15-year repayment with an annual interest rate of 7.5% when the monthly repayment capacity is 45,000 yen, first select "45000" and "ENT".
Enter the payment amount (PMT) by operating the "PMT" key. Next, "7.5", "÷", "12", "=", "E"
Enter the interest rate (i%) by operating the "NT" and "i%" keys. In this case, since the payment is made monthly, the monthly rate "0.625 (%)" is corrected and input by the calculation of "7.5 / 12 =".

Next, "15", "x", "12", "=", and "EN"
The period (N) is input by operating the T and "N" keys. In this case, since it is a monthly payment, 1 is calculated by calculating "15 x 12 ="
I am re-entering the number of months "180" for 5 years. After inputting the three sets of items as described above, the output of the loan is instructed, but if the payment is at the end of the period, the key operation of "ANS" and "PV" is performed, and if it is the payment at the beginning of the period, "ANS" and "ANS". "
The key operation of "PV" is performed.

By the above key operation, the arithmetic processing is executed according to the flowchart of FIG. 6 to obtain the debt.
When the above key operation is performed, "PMT" is input, but "FV" is not input. Therefore, in FIG. 6, steps B2 to B3, B6 and step B are performed.
Proceed to 7 and B8, and step B according to the discrimination flag Fa.
The end-of-year loan calculation of 9 or the beginning-of-year loan calculation of step B10 is executed. That is, "ANS""P
When the "V" key is operated, the flag Fa is "1", so the term-end payment loan calculation in step B9 is executed, and the calculation result is "48554304.207".
Yen is displayed on the display unit 2 as the borrowable amount. At this time, the display unit 2 displays the letters “LOAN” indicating loan calculation and the letters “END” indicating end-of-term payment.

When the "ANS", "ANS", and "PV" keys are operated, the flag Fa becomes "2", and therefore the beginning payment loan calculation of step B10 is executed.
The calculation result “4884643.308” yen is displayed on the display unit 2 as the borrowable amount. At this time, the letters “LOAN” indicating loan calculation and the letters “BGN” indicating beginning payment are simultaneously displayed on the display unit 2.

FIG. 10 shows a specific key operation and display example when performing reserve calculation. For example, if you want to calculate the accumulated interest of 2,500 yen per month at a compounded monthly interest rate of 6% per year for 5 years, first calculate "5", "x", "12", "=", and "ENT.""N"
Key is operated to input the period (N). In this case, since the compound interest is monthly, the number of months for 5 years is changed to “60” by the calculation of “5 × 12 =”.

Next, "6""÷""12""=" and "EN"
Input the interest rate (i%) by operating the key "T""i%". In this case, since the compound interest is monthly, the annual interest rate is corrected to "0.5 (%)" and input by calculating "6/12 =". Next, the monthly reserve amount (PMT) is input by the key operation of "2500", "ENT" and "PMT". Then, after inputting the three items as described above, the output of the total interest and interest is instructed. When the payment is made at the end of the period, the key operation of “ANS” and “FV” is performed, and when the payment is made at the beginning of the period, “ANS” is displayed. "A
Key operations of "NS" and "FV" are performed.

By the above key operations, the arithmetic processing is executed according to the flowchart of FIG. 6, and the total interest and interest is obtained. When the above key operation is performed, both "PMT" and "FV" have been input, so in FIG. 6, steps B2, B3, B6 and B12, B13 are executed.
Then, depending on the discrimination flag Fa, the end-of-year payment reserve calculation of step B14 or the beginning-of-year payment reserve calculation of step B15 is executed. That is, when the key operation of "ANS" and "FV" is performed, the flag Fa becomes "1", and therefore the reserve calculation at the end of the period of Step B4 is executed, and the calculation result "174425.0762" yen is the sum of the principal and interest. The amount of money is displayed on the display unit 2. At this time, the display unit 2
The letters "SF" indicating the reserve calculation and "E" indicating the end of term payment
The letters "ND" are displayed.

When the "ANS", "ANS", and "FV" keys are operated, the flag Fa becomes "2", and therefore the beginning payment loan calculation of step B15 is executed.
The calculation result “175297.2016” yen is displayed on the display unit 2 as the total amount of principal and interest. At this time, the display unit 2 displays the characters "SF" indicating reserve calculation and the characters "BGN" indicating beginning payment.

By simply inputting the data of the three items as described above, a calculation formula for the data is derived, and a desired financial calculation is performed based on the formula. If you change the input contents in the middle of the input, if you calculate the formula with priority on the second input, you do not need to change the mode or clear the previous data and input the next data. The operation can be simplified.

In the above embodiment, the presence / absence of "PMT" and "FV" is checked to determine the corresponding formula, but in addition, "PMT" and "PV" or "FV" are used. Alternatively, "PV" may be checked to determine the corresponding calculation formula. Further, in the embodiment, the case where the invention is applied to the electronic wristwatch is shown, but the invention can be similarly applied to other general small electronic calculators.

[0050]

As described above in detail, according to the present invention, in a computer for financial calculation, a corresponding calculation formula is automatically judged from the inputted data and its order, and the judgment result is displayed. Since the calculation process is performed according to the above calculation formula and the calculation result is displayed, the desired financial calculation can be performed only by inputting the data without setting the calculation mode in advance. Therefore, it can be applied to a small electronic calculator, particularly a wristwatch with a calculation function in which the number of keys is limited, to exert a great effect.

[Brief description of drawings]

FIG. 1 is a front view showing an external configuration when a financial computer according to the present invention is applied to an electronic wristwatch.

FIG. 2 is a diagram showing an electrode configuration of a display unit.

FIG. 3 is a block diagram showing a configuration of an electronic circuit.

4 is a diagram showing an internal storage configuration of a RAM shown in FIG.

FIG. 5 is a flowchart showing the overall schematic operation.

6 is a flowchart showing details of the arithmetic processing operation in FIG.

FIG. 7 is a flowchart showing a setting operation of a flag Fa associated with an ANS key operation.

FIG. 8 is a view showing a specific key operation and a display example at the time of compound interest calculation.

FIG. 9 is a diagram showing a specific key operation and a display example during loan calculation.

FIG. 10 is a diagram showing a specific key operation and a display example at the time of reserve calculation.

[Explanation of symbols]

 1 Watch Case 2 Display Section 3 Keyboard 4 Shift Key 5 ANS Key 6 ENT Key 7 Time / Data Display Section 8 Date Display Section 9 Mode Key 11 ROM 12 ROM Address Control Section 13 Arithmetic Circuit 14 RAM 15 Instruction Decoder 16 Latch Circuit 18 Oscillator 19 Timing pulse generator 20 Frequency divider 21 Key input unit 22 Display buffer 23 Buzzer

Claims (1)

[Claims] 1. A financial calculator that performs financial calculations such as compound interest calculation, loan calculation, and funded calculation, and a calculation formula storage unit that stores a plurality of financial calculation formulas in advance, and a payment that stores payment amount data per payment. Amount data storage means, principal and interest total data storage means for storing principal and interest total data, first discrimination means for discriminating whether or not the payment amount data is stored in the payment amount data storage means, and the principal and interest total data The second determination means for determining whether or not the total interest and interest data is stored in the storage means, and the compound interest calculation when it is determined by the first determination means that the payment amount data is not stored. And the first determination means determines that the payment amount data is stored, and the second determination means does not store the total interest and interest data. When it is determined, the loan calculation is executed, it is determined that the payment amount data is stored by the first determination unit, and the total interest and interest data is stored by the second determination unit. A financial calculator comprising: a financial calculation means for executing the reserve calculation when the above is determined; and a display means for displaying a calculation result by the financial calculation means.