tApCalc Finance

User Manual

Getting Started

User Interface

About User Interface

tApCalc Finance provides a very simple and easy to use user interface suitable for a device with touch stylus interface. All keys and commands that tApCalc Finance understands are made available through the user interface and there is no external dependency on Pocket PC Keyboard or character recognizer. The user interface has the following elements.

· Keys that you tap for entering data to tApCalc

· Results are displayed on the calculator display area (right above the keys) and the tape area which is above the area that calculator keys are displayed on.

· There is a “New” menu that allows switching between one versions of tApCalc to other if installed.

· Tools menu provides all tape and IR related functions.

Setting calculator preferences

There are 2 preferences you can set for tApCalc Finance:

Number of decimal places preference will set the number of digits after decimal place that the calculator needs to display. The value can be set from 0 to 4
Save format can be set to “Tab delimited” or “CSV Format”. Most text files are usually tab delimited. However, if you want the tape to be used by other programs that understand CSV format, including Microsoft Excel, you should select CSV format.

Calculator keys

About Calculator keys

tApCalc Finance has different types of keys, Number keys, Unary keys, Binary keys, and flag keys. It is not a RPN calculator. Therefore, you must use the keys as you would use a normal calculator that does not follow RPN.

When you are in tApCalc screen, you must use the number and operator keys displayed on the tApCalc screen. tApCalc will not recognize any key entered using the on screen keyboard of Pocket PC.
Number input must always follow an operator input, which marks the end of number input for tApCalc. If you are ending a calculation and do not have any more operators to input, a “=” must be entered to mark the end of calculation.
If after pressing “=” key you need to continue with the operation, you do not need to enter the result displayed on the calculator again. Just go ahead and enter the operator you desire.

Binary Function Keys

Binary keys are the keys that require 2 inputs to work on. Example of binary keys are +, - , /, X etc.

When a Binary key is pressed, a second operand number must be entered followed by another operator to indicate end of operand input for the binary operator. For example, to add 10+20+50 you will need to enter “10”, “+”, 20,”+”,”50”. Here, the first + indicates end of input for number 10, and the second + for 20. Therefore, after second + is entered, tApCalc will evaluate 10+20 and display 30 on the display.
Now the natural question is what to do after entering “50”? If you calculation ends here, you must enter the operator “=” to indicate end input for 50. Otherwise, you should enter the corresponding calculator key for the function you want to apply to the above result.

Unary Function Keys

Unary keys are the keys that require only a single input and are evaluated as soon as the operand is pressed.

Example of unary keys is 1/x, Sqrt, M+ etc. When a unary key is pressed, it is applied on the last result displayed on calculator display, and the calculator immediately displays the new result after applying the operator.
All memory keys are unary keys.

Financial Function Keys

Financial keys are the keys used to carry out the financial operations. Following financial keys are available in tApCalc.

Time Value of Money (TVM) Keys

TVM keys are Present Value (PV), Final Value (FV), Payment (PMT), Interest Rate (i), Periods (n), Amortization (AMO).

These keys are used in tandem to calculate Time Value of Money. In addition, a %12 and x12 keys are available.
Flag keys Beg (Begin) and End (End) are provided to set the payment date at the beginning or end of the month.
%12 Key will do 3 things. It will terminate the current number, divide the number input by 12 and store the result in Interest Rate (i).
x12 key will do 3 operations. It will terminate the current number, multiply the number input by 12 and store the result in Period (n).
The sequence of using these keys for a financial operation is described in TVM Functions.
These keys can also be used to calculate Amortization. It is explained in Amortization section.

Discounted Cash Flow (DCF) Keys

tApCalc support 2 DCF functions, Internal Rate of Return(IRR), and Net Present Value (NPV). In order to calculate these, 5 keys are available. CF0, CFj, Nj, IRR and NPV.

CF0, CFj and Nj are used to provide cash flow values and repeated cash flow values.
You will also need to use additional financial keys to calculated IRR or NPV
The sequence in which these keys need to be used for the underlying financial operation is described in DCF Functions.

Depreciation Keys

tApCalc provides functions to calculate depreciation of assets. It supports 3 forms of depreciation calculation, Straight Line (SL), SYD, and Declining Balance (DB) methods of depreciation. The 3 keys SL, SYD, DB are used for this.

These keys are used in combination with the TVM keys PV, FV, n, and i to calculate depreciation.
The sequence in which these keys need to be used for the underlying financial operation is described in Depreciation Functions.

Bond Calculation

tApCalc provides function to calculate semi-annual bond yield and price. The keys used for calculating bond are YTM, Price, p.Dt, m.Dt. In addition there is a flag key m.dt available to indicate to tApCalc that the data entered is a date not a number.

When entering a date for Bond calculation, you will have to enter 6 digits after decimal point but the maximum number of digits after decimal in tApCalc is 4. Besides, you will have to go back and forth between preferences and calculator to set the preference. By clicking on m.dt button, you will notify tApCalc to accept 6 digits after decimal, as input because you are entering date, not a number.
The sequence to calculate Bond Price and yield is described in the section Bond calculation.

Tape Functions

About Paper tape simulation

tApCalc Finance provides a simulated paper tape that comes in handy many ways. Most hardware financial desk calculators come with a paper tape or printer attached to it that records all calculation for future reference. Paper tape simulation in tApCalc does exactly that and more. In case of tApCalc tape, a tape saved to the disk can be reloaded, edited for mistakes and rerun without reentering all data again, thus saving valuable time for the user. Lets say you have to do some calculations and you do not have all data handy, you can start the calculation using tApCalc, enter the known data and save the calculation to a tape file. In a future time, when you have the remaining data you can load the tape and extend the calculation with new data.

tApCalc provide the following functionality with the tape:

Save tape
Load tape
Edit tape
Run tape
Clear tape
Send tape to IR
Receive tape from IR

Save tape

Save tape will save the entire content of the currently displayed tape on to My documents\Calc\tApCalcFinance directory on your Pocket PC Device

Select “Save tape” menu item from “Tools” menu to access this function.

If no tape is currently open and the program has Untitled displayed in the Title bar, it will directly go to the “Save” dialog box screen. This screen will display Untitled as the tape name and blank in the Comments line.
Enter the name of the file you want to save your tape to, enter a comment line if you want to and click on Ok. The comments line is saved at the beginning of the tape for you to recognize later what the tape is about. Providing a comment line and saving the tape does not affect load tape function.
If you have opened a tape and added additional calculation to it and then selected the Save tape menu item, tApCalc will display a dialog box asking if you would like the save the new calculations to the same tape that you had opened. If you want the currently opened tape overwritten, click on Yes, otherwise click on No and tApCalc will enter the “Save” dialog box for you to specify a new file name for the tape and a comment.

Note: The name of the currently loaded tape is always displayed at the title line of tApCalc e.g. tApCalcFinance(mybudget.txt). If no tape is currently open, the heading will display tApCalcFinance(Untitled).

Load tape

Use load tape option to load a previously stored calculation from the directory My documents\Calc\tApCalcFinance directory on your Pocket PC Device.

Select “Load tape” menu item from “Tools” menu to load tape

In the load dialog box, you can only select a previously saved tape in the My documents\Calc\tApCalcFinance directory. Tap on the tape you want to load.
Tap in what way you want to load the tape. The tape can be loaded as a program to the calculator or as an output file. Tap on the appropriate button and then on Load button to load the tape.
Tapping on delete button will delete the tape.
If you do not wish to load any tape, tap on cancel

Note: If you selected Output instead of User Program, the tape will not be loaded to the calculator as a calculation. Rather, it will open a text window and display the data stored in the tape. This is the Output screen from where you can print the tape.

Edit Tape

Edit tape function can only operate on tapes displayed on the calculator screen. Therefore, it will be active when the tape is on and you have entered some calculations, or you have loaded a previously stored tape.

Select “Edit tape” menu item from “Tools” menu to edit tape. It will be enabled if there is any content on the tape.

You can make changes to any operator or operand. To change an operator or operand, tap on that line. Then, if you enter an operand, the operand will be changed and if you enter an operator, the operator will be changed.
To enter comment on the line, tap on left side of the line. You will see a box where you can enter text.
Please note the line with (NE) at the end of them. This means Not Editable. These are the results of previous operations that are displayed on the tape and recalculated after you make changes to the operators and operands on the tape. These cannot be changed.
If you made a mistake on changing a line, use <Undo> to discard changed to the line.
If you made mistakes and want to discard all changes, click on <Cancel>
<Done> will enter “Edit” mode and keep the changes you did intact. In most cases, the tape will be reevaluated and the lines that had (NE) with them will have new numbers.

Run Tape

Run tape function to rerun the calculations from the beginning as if the user enters all the data from the beginning. This is equivalent to programming. Run is primarily useful when you want to load a tape to extend the calculation or edit a tape for mistakes.

Select “Run tape” menu item from “Tools” menu to run tape. It will be enabled only when there is any contact in the tape.

When the tape is run, you will see the calculation being reevaluated in the calculator display. At the end of the run, the calculator will display the final result and you can continue adding new calculations to the tape normally.

Clear Tape

Clear tape clears the tape content.

Select “Clear tape” menu item from “Tools” menu to clear tape. It will be enabled only when there is any contact in the tape.

Beam Tape in

This function comes in handy when you want to send a calculation done by you to another PDA without going through the lengthy process of emailing it.

Select “Send to Infrared” menu item from “Tools” menu to beam the content of the tape.

It will only work when there is tape content displayed to be beamed. If you need to beam a preciously saved tape, load the tape using “Load Tape” option and them use this feature.
When beaming the tape, it will be received at the other PDA you are being to as a text file.

Beam Tape out

This function comes in handy when you want to receive a tApCalc calculation, or a txt file in tApCalc text format from another PDA.

Select “Receive from Infrared” menu item from “Tools” menu to beam the content of the tape.

This option will open the Pocket PC Beam utility and wait to received a tape in the form of a text file.
If a text file is not received, or the file is not in the tApCalc tape format, an error message to that effect is displayed.

Financial Functions

Amortization

Amortization calculations produce the amount applied toward the principal and interest for a particular loan payment or series of payments.

To amortize a loan payment, follow the following steps:

1. Clear the financial registers by pressing C

2. Key in the loan amount and then press PV.

3. Key in the interest rate and press i.

4. Key in the payment amount and press ± , PMT.

5. Key in the number of payments you wish to have amortized and press AMO .

6. The amount applied towards interest is now shown in the display.

Example: Suppose you have purchased an automobile for $25,000 at 8.75% interest compounded monthly on a 5 year loan. Find the amount you will have paid in interest and principal on the loan after 10 months.

1. Press C to clear the financial registers.

2. Press END for end mode.

3. Key in 25000 and press PV to enter the loan amount.

4. Key in 8.75 and press ¸12 to enter the interest compounded monthly.

5. Key in 5 and press ´12 to enter the number of months.

6. Press PMT to calculate the monthly payment, which will show as 515.9357.

7. Key in 10 and press AMO to amortize the loan.

The program will display the following on the tape

(Int Paid) 1,711.3645 indicating the amount of interest you have paid in 10 months

(Principal Paid) 3447.9925 indicating the amount you have paid towards principal in 10 months after 10 months

(PV) 21,552.0075 indicating the remaining principal balance after 10 months.

Note: Please note that you actual numbers may be slightly different because of preferences setting. If your preferences are set to 2, then the i value calculated will be rounded to next higher decimal point value causing the difference.

Bond Calculations

The PRI and YTM functions calculate the price and yield to maturity of a semi-annual coupon bond. Calculations are made on a 30/360 basis using a par value of 100.

Example: You are interested in purchasing a 7.25% semi-annual coupon bond at 92.25. Determine the yield this bond will produce if you purchased it on Oct 10, 1987 and it matures on Oct 10, 1997.

Key in 7.25 and press PMT to enter the coupon rate.
Key in 92.25 and press PV to enter the bond price.
Press m.dy to use Month-Day-Year format.
Key in 10.101987 and press p.dt to enter the purchase date.
Key in 10.101997 and press m.dt to enter the mature date
Press YTM the yield to maturity.

The bond will yield 8.4%.

Example: Assume you desire a yield of 8.88% on a bond that reaches maturity on October 10, 1998. If the bond is a 7.75% treasury bond, how much should you pay for it on October 10, 1988?

Key in 7.75 and press PMT to enter the coupon rate.
Key in 8.88 and press i to enter the desired yield.
Press m.dy to use Month-Day-Year format.
Key in 10.101988 and press p.dt to enter the purchase date.
Key in 10.101998 and press m.dt to enter the mature date
Press PRI to calculate the price.

You should pay $92.7096 for the bond.

Depreciation

Depreciation calculations can be performed using Straight Line (SL), Sum of Years Digits (SYD), or Declining Balance (DB) methods.

To calculate depreciation using any method:

1. Key in the price of the asset and press PV

2. Key in the salvage value and press FV

3. Key in the length of time (in years) of the asset's usefulness and press n

4. If you are using the declining balance method, key in the percentage declining balance factor and press i

5. Key in the length of time (in years) to calculate the depreciation on and press either SL or DB or SYD.

Example: Compute the depreciation on a $8600 computer workstation after 1 year. Assume the workstation will be depreciated over 6 years and that the Sum of Years Digits method will be used.

1. Key in 8,600 and press PV

2. Key in 0 and press FV.

3. Key in 6 and press n.

4. Key in 1 and press SYD. The depreciation for the first year is $2,457.1429.

To compute the depreciation after the 2nd year, key in 2 and press SYD.

The depreciation after the second year is $2,047.619

Time Value of Money Calculation

Loan Calculation

Example: Suppose you wish to take out a Car loan. Calculate the monthly payment if your loan is for $9,000 at 7.95% interest compounded monthly for 7 years.

1. Press C to clear the financial registers.

2. Key in 9,000 and press PV to enter the loan amount.

3. Press End to make sure end-mode is being used.

4. Key in 7.95 and press ¸12 to enter the interest rate per period.

5. Key in 7 and press ´12 to enter the number of compounding periods.

6. Press PMT. The monthly payment is $140.0518.

Example: How much could you afford to pay for a new car if you could afford $450 monthly payments? Assume a 6year loan with 7.25% interest compounded monthly.

1. Press C to clear the financial registers and set end mode.

2. Key in 450 and press PMT to enter the monthly payment amount.

3. Key in 7.25 and press ¸12 to enter the interest rate per period.

4. Key in 6 and press ´12 to enter the number of periods.

5. Press PV to calculate the purchase price.

The amount you could afford to pay for the car is $26,209.2679.

Mortgage Calculation

Example: How much would your monthly payments be for a house costing $170,000 at 9.75% compounded monthly on a 25 year loan?

1. Press C , End to clear the financial registers and use end mode.

2. Key in 170,000 and press PV to enter the purchase price.

3. Key in 9.75 and press ¸12 to enter the interest rate per compounding period.

4. Key in 25 and press ´12 to enter the number of periods.

5. Press PMT to compute the monthly payment. The result is $1,514.9336.

The result is negative because it represents an amount paid out.

Example: Calculate the payments for the first 2 years of a variable rate mortgage if the interest rate is 9.75% for the first year and 10.25% for the second year. The loan amount is $180,000 and has a 15year term.

1. Press C, End to clear the financial and select end mode.

2. Key in 180,000 and press PV to enter the loan amount.

3. Key in 15 and press ´12 to enter the number of compounding periods.

4. Key in 9.75 and press ¸12 to enter the 1st year's interest rate

5. Press PMT to calculate the payments for the 1st year.

The result is $1,906.8528.

6. Key in 1 and press ´12, FV to calculate the remaining balance after the 1st year. The result is $174,422.9092.

7. Key in the result of FV with sign change(i.e. 174,422.9092), and press PV to store the new loan amount.

8. Key in 14 and press ´12 to enter the new number of compounding periods.

9. Key in 10.25 and press ¸12 to enter the new interest rate.

10. Key in 0 and press FV since the loan will be paid off at the end.

11. Press PMT to calculate the 2nd year's payments.

The result is $1,959.2811.

Savings Calculation

Example: Suppose you have $7,000 in a savings account. You have just received a raise and are able to make monthly deposits of $550 into this account. How long will it be before you have $19,000 if your account earns 6.75% interest compounded monthly?

1. Press C , End to clear the financial registers.

2. Key in 7,000, ± and press PV to enter the beginning amount.

3. Key in 550, ± and press PMT to enter the monthly deposit.

4. Key in 6.75, press ¸12 to enter the interest rate per compounding period.

6. Key in 19,000 and press FV to enter the future value.

7. Press n to calculate the number of periods.

The result is 19 months.

Example: A savings account has a $100,000 balance and earns 8.25% interest compounded monthly. How long will it take before the account is depleted if regular monthly withdrawals of $1800 are made at the beginning of each month?

1. Press C , Beg to clear the financial registers and select begin mode.

2. Key in 100,000 and press PV to enter the balance.

3. Key in 8.25 and press ¸12 to enter the interest rate per compounding period.

4. Key in 1800 and press ± , PMT to enter the monthly withdrawal.

5. Press n to calculate the number of months to deplete the account.

The result is 70 months (5.8333 years).

Discounted Cash Flow Analysis

The Net Present Value, and Internal Rate of Return functions allows you to compute compound interest problems at regular intervals where the payment (positive or negative) amount is irregular. In addition, if a number of the amounts are regular, you can "group" them together. You must observe the Cash Flow Sign Convention when entering the payment amounts.

The NPV function calculates the net present value of a series of cash flows made at regular intervals. It is most commonly used to perform an analysis between a variety of investment opportunities. A negative NPV represents a loss on an investment.

Example: Suppose you are considering purchasing a hotel for an initial payment of $150,000. You predict that cash flows for the first 3 years to be $50,000 each year, $65,000 for the 4th year, and $75,000 for the 5th year. You desire a 20% return on investment. Can this amount be realized?

1. Press C to clear the financial registers.

2. Key in 150,000 and press +/-, CFo to enter the initial cash outlay.

3. Key in 50,000 and press CFj To enter the 2nd cash flow.

4. Key in 3 and press Nj to "group" 3 cash flows at 45,000.

5. Key in 65,000 and press CFj to enter the 4th cash flow.

6. Key in 75,000 and press CFj to enter the 5th cash flow.

7. Key in 20 and press i to enter the interest rate.

8. Press NPV to calculate the net present value.

The result is $16,811.3426

8. Press IRR to calculate the Internal Rate of Return. The investment would yield 24.6367%.

Note: Please note the cash Flow Sign Convention. Compound interest calculations involve money being received as well as paid out. For example, if you take out a loan, you initially receive money (positive) and then make periodic payments (negative). Thus a loan calculation would involve a positive present value and a negative payment.

tApCalc Finance

User Manual

Contents

Getting Started

Calculator Key Convention

Tape Functions

Financial Functions

Getting Started

User Interface

About User Interface

Setting calculator preferences

Calculator keys

About Calculator keys

Binary Function Keys

Unary Function Keys

Financial Function Keys

Time Value of Money (TVM) Keys

Discounted Cash Flow (DCF) Keys

Depreciation Keys

Bond Calculation

Tape Functions

About Paper tape simulation

Save tape

Load tape

Edit Tape

Run Tape

Clear Tape

Beam Tape in

Beam Tape out

Financial Functions

Amortization

Bond Calculations

Depreciation

Time Value of Money Calculation

Loan Calculation

Mortgage Calculation

Savings Calculation

Discounted Cash Flow Analysis