"Directions on how to use the "Financial Calculator"on the Palm Treo
Remember from the class, tap on calculator and use your thumb to hit the right side of the navagator.
Before you begin to solve each problem, you might want to clear away any
residual results or input parameters of earlier calculations.
You can do this pressing the "Edit" button then the "Clear" key.
The six financial function keys are:
N Number of periods
APR Periodic Interest rate
P/Yr Periodes per Year
PV Present Value
PMT Periodic PayMenT, and
FV Future Value
The basic strategy for solving financial problems is to enter a value
into five of the six financial registers using their respective buttons and then tell the calculator to
solve for the sixth parameter. To solve you need to enter the calculation mode with the "Edit" button then use the "Solve" button to get your answer.
Negative amounts are used to indicate money that flows away from you.
These are cash outflows or disbursements. Whenever you pay for something with
cash (or an equivalent), you have a negative cash flow.
Whenever you make a payment on a loan, that is a negative cash flow.
When you receive money, that's a positive cash flow.
Positive cash flows occur when you sell something for cash, or borrow money.
How to...
Solve for the Principal and Interest on a home and
show the payment schedule.
Suppose you would like to know how much it will cost per month in
Principal and Interest to buy a new home.
The builder is asking $255,000 for a new home, the interest rate for
a 30 year amortized mortgage is 6.25% and you
have a down payment of about $20,000.
Saving $10,000 for closing costs, you plan on borrowing $245,000
enter 245,000 press PV (Positive, initially received from the bank)
enter 360 press N (30 * 12 )
enter 6.25 press APR
enter 12 press P/Yr
enter 0 press FV
Press the Edit button to enter the calculation mode.
Payment Mode: End
Pmt should be cleared, not zero, after clicking "Solve", it should show
Pmt as $-1508.507
Once you enter the Payment mode the screen changes and you can stay there to try more calculations.
Click on "Done" then click on "Amrt" to show the entire payments schedule on a
monthly basis. This will show how much is paid towards the Principal and
Interest as time progresses in a spreadsheet format.
( yes, I know... what an amazing little tool !! )
If you click on Runnning Totals you will see that at the end of the
30 years the loan will have cost the borrower $298,062.57 in interest.
Solve for the Balance on a mortgage loan after 10 years
Suppose that you have been paying your mortgage for ten years and you
would like to know how much you still owe.
When you initially purchased the house you took a standard 30 year
amortized mortgage of $250,000 and your monthly payments have been $1300.
enter 250,000 press PV (Positive, you received that amount initially from the bank)
enter 120 press N (10 * 12 )
enter 6.25 press APR
enter 12 press P/Yr
enter 1300 press +/- to show -1300 then press Pmt (Negative, payments to the bank)
Press the Edit button to enter the calculation mode
Payment Mode: End
FV should be clear, not zero, after hitting "Solve", it should show
FV as $-250,346.09 !!!
This means your monthly payments were barely enough to cover the
interest payments on the loan for the last 10 years and you still
owe about the same amount as when you initially purchased your house.
If you redo this loan with a N of 360 and a FV of 0 with the
Pmt as unknown you will find that the standards payments to
amortize this loan fully should be around $-1539.29 per month.
Solve for the equity on your home
Suppose you would like to know how much equity you have in your home.
The equity is the value of the house less what you owe on the mortgage.
What you know is that you borrowed $175,000 to buy the house 5 years ago and
you have 15 years to pay on the mortgage. The interest rate on the
mortgage is 6.25% and the tax appraisal district says that the house is worth $220,000.
Your monthly payments are $1279.12 (P&I). What is your equity?
This is a two step problem. The first step is to figure out how much you owe.
You know that you have 180 (15 X 12) months to pay on the loan, the
interest rate is 6.25% (annual), your monthly payments are $1279.12 and the balance of
the loan at the end of the 180 months will be zero.
enter 6.25 press APR
enter 12 press P/Yr
enter 180 press N (15 * 12 )
enter 1279.12 press +/- to show -1279 then Pmt (Negative, disbursement to the bank)
enter 0 press FV
Press the Edit button to enter the calculation mode.
Payment Mode: End
PV should be clear, not zero, after hitting "Solve", it should show
PV as $149,181.93
Subtract that from the appraised value ($220,000) and you'll have your equity.
Your equity is about $70,818 and seven cents.
Solve for Number of Payments to pay off debt (out cash flow)
Suppose that you owe your credit card company a total of $5,950 and
you would like to pay off the balance.
How long will it take you to pay it off if the credit card company
charges 18.75% annual interest and you can afford to pay $120 per month?
enter 5,950 press PV
enter 0 press FV
enter 18.75 press APR
enter 12 press P/Yr
enter 120 press +/- to show -120 then press Pmt (Negative, disbursement to the bank)
Press the Edit button to enter the calculation mode.
Payment Mode: End
N should be clear, not zero, after hitting "Solve", it should show N as 96.135
It will take 96 monthly payments of $120 to pay off this debt at this interest rate.