Welcome to the

One+One™ 2.3

Advanced Scientific Calculator


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What is One+One?

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Thank you for evaluating One+One. One+One is an algebraic scientific and financial calculator for the Palm OS. The calculator supports double precision accuracy and has 80 scientific functions including 5 financial functions, 4 number bases, and 8 statistical functions. There are 20 memory registers (two banks of 10 each). In addition, One+One supports graffiti input, copy and paste, and international number formats.

Personalize your copy of One+One. Choose from six different keyboard color schemes (two for B&W devices).

Technical specifications

What is new in Version 2.3?

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Version 2.3 adds:

Version 2.2 added:

Version 2.1 added:

Version 2.0 adds many exciting new features to One+One.

Other changes

Thanks to everyone who submitted suggestions!

System Requirements

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One+One requires Palm OS 3.0 or higher, and 184K of RAM.

One+One works on any handheld device that is running Palm OS 3.0 or higher including all devices from Palm, Inc. (Zire, Tungsten, Treo, and LifeDrive) as well as the Handspring Visors, the Sony CLIE, the HandEra, and the IBM Workpad. One+One has been enhanced to take advantage of the high resolution screens.


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To install One+One simply unzip the archive you downloaded and use the install tool (or equivalent) to install One+One.prc on your Palm device. You might also consider assigning the calculator button to bring up One+One instead of the default calculator after syncing. To do this, go to the Prefs application, select Personal, and then Buttons. Select One+One from the list next to the button you wish to reassign.

To uninstall One+One, simply delete One+One via the Palm applications screen.


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One+One features a free 15 day trial. All the features of One+One are available during the trial. The only difference between the trial and a registered version is that the registration screen no longer displays on startup. After the 15 day trial, the five key (5) becomes disabled. If you decide that you like One+One, purchase a registration code to unlock it.

To unlock One+One you need a registration code. A registration code can be obtained by purchasing One+One from Creative Creek, LLC. You must provide the user name shown in the registration screen to obtain a valid code. The code will be e-mailed to you.

To register your software, select the Display->Registration menu item to bring up the registration screen.

Use graffiti (or the popup keyboard) to enter the registration code you received in the mail into the field following "Reg. code:" and tap OK. If the code you typed in is accepted, the screen will disappear and the One+One keyboard will be displayed. If you make a mistake in entering in the code, a dialog will indicate that the code wasn't valid and you will be given a chance to edit the code. If you wish to dismiss this dialog without entering a registration code, simply remove all the characters from the Reg. code field and tap OK.

If for any reason you have trouble registering your software please contact us via the Contact page for assistance.

Basic Operations

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One+One is an algebraic calculator with precedence. This means that operations in an expression like (1+2*3) One+One completes the highest precedence operation before completing the lower precedence one . In this case the answer is 7 and is computed as 1 + (2*3). All unary operations like , , , , etc. have the highest precedence and operate immediately on the value in the display. The binary operations have the following precedence

, highest precedence
, lowest precedence

Parentheses can be used to control the order of computation. completes all operations. Up to 31 operations can be pending at one time. If you exceed this, One+One will produce an error (and clear all pending operations).

Most buttons on One+One can access three functions.

The function or number in the middle of each button is accessed without shifts. The function at the top of the button is accessed by pressing the 2nd-shift key before pressing the button. The 2nd-shift indicator will light in the display when the 2nd-shift is active. Similarly to access the functions above the buttons use the 3rd-shift key . The 3rd-shift indicator will light in the display when the 3rd-shift is active.

Most functions remember the last value used during a computation. This value can be accessed via the button.

One+One Walkthrough

(A guide to the One+One interface)


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(main screen)

(main screen)


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The preference screen is displayed when you choose Display->Preferences from the menu or when you tap the degree indicator on the screen (see walkthrough above).

Press OK to commit your changes. Press Cancel to leave them as they were.

Basic Functions

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Change sign of mantissa or exponent
Start entering exponent
Clear calculator and all pending operations.
Undo last character (or clear calculator)
Control order of operations. When any parentheses are still open (pending), the display shows () in the lower right corner.

One+One allows you to input numbers using Graffiti. The characters 0 through 9, decimal, minus sign and 'e' can be used instead of the numeric buttons, , , and . In hexadecimal mode, you must use Graffiti to enter the letters A through F.

Keyboard and Treo Support

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One+One allows you to input numbers using Graffiti or by pressing keys on the Treo keyboard or an external keyboard. The characters 0 through 9, decimal, minus sign and 'e' can be used instead of the numeric buttons, , , and . The characters '+', '-', '*', '/' can be used instead of , , and . In hexadecimal mode, you must use Graffiti or the keyboard to enter the letters A through F.

On the Treo, the keyboard is automatically option-locked into numeric mode. Letters like 'e' that share space with the numbers can be accessed by pressing option before pressing the key. After each press, the keyboard will automatically return to numeric mode.

When in hex mode, the keyboard is automatically locked into alpha mode in order to make entering A-F easier. To enter numbers, press option before each number or use the One+One keypad.

5-way Button Support

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On devices with the 5-Way navigation button, the 5-way can be used to highlight and select the buttons on the keypad.

International Number Formats

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One+One honors the number format chosen in the Prefs application. If you find that One+One is displaying numbers using the wrong decimal or thousands separator, go to the Prefs application and choose Formats from the popup menu. Choose the number format for your locale from the Numbers: popup.

For number formats that use the comma as the decimal separator, One+One displays instead of for the decimal button. Changing the number format affects the way values are displayed, copied, and interpreted during a paste.

Register Functions

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One+One has 20 registers -- 10 primary registers and 10 secondary registers. Only the primary registers are accessible directly from the keyboard. The secondary registers are used to store values used for the financial and statistical functions. To access these registers, swap the primary and secondary registers via and then access the values now accessible via and . Use to swap the registers back to their original configuration when done. The secondary registers can be used to store your own values but you must be careful not to use any financial or statistical functions if you do so.

n Store into register n
n Store into secondary register n (register 10+n)
n, n Add contents of x register to register n
n, n Subtract contents of x register from register n
n, n Multiply register n with contents of x register
n, n Divide register n by contents of x register
n Recall from register n
n Recall from secondary register n (register 10+n)
Swap primary and secondary banks of registers
Clear all registers
Swap x and y registers
Recall last x value
Clear x register (and all pending operations)
n Set display to fixed format with n decimals displayed
n Set display to scientific format with n decimals displayed

The registers can be viewed by choosing Display->Registers from the menu or by tapping the key twice.

Choose OK to return to One+One

Displaying the registers is an easy way to see the values of the financial registers. Note that the interest (i) is displayed as fractional interest and not in percent as it is when you compute it using the button.

Scientific Functions

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Unary Functions

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These functions operate on the value in the x register and replace it with the function result.

The trigonometric functions are sensitive to the angle mode: degrees, radians, or grads (, , or in the display where 360 degrees = 2 pi radians = 400 grads).

Set the angle mode using the Preferences dialog (available from the Display menu).

Key Function Description Type
  2nd shift. Use to access functions at the top of each button.  
  3rd shift. Use to access the functions above each button.  
  abs Absolute value unary
cbrt Cube root unary
  chop Round value to display precision unary
  mod Modulo (y - x * floor(y/x)) binary
pi Value of pi unary
ln Natural logarithm (base e) unary
ln1p ln(1 + x) more accurate for x near zero unary
log Base 10 logarithm unary
exp Exponential function unary
  expm1 exp(x) - 1 more accurate for x near zero unary
pow10 Ten to the x power unary
ytox y to the power of x binary
sq Square unary
sqrt Square root unary
inv Reciprocal unary
frac Fractional part unary
int Integer part unary
  floor largest integer smaller than or equal to x unary
  ceil smallest integer larger than or equal to x unary
  fact Factorial unary
% Percent (y * x) / 100 binary
% ch Percent change 100 * (x - y) / y binary

The int and frac functions round to 9 decimal digits before determining the integer and fractional parts. Under this definition frac is computed using the formula

frac(x) = x - int(x)

Most of the time this produces the desired results but does treat the input as if it only had 10 digits of accuracy. One of the ramifications of this is that the fractional part doesn't always have the same sign as x. Take for example the number 1.99999999964 (i.e. 2 - 36e-11). When displayed in One+One this number looks like it is 2.0. Because of the rounding int(x) is 2 (as expected) while frac(x) is -36e-10.

The ceil, round, and floor functions do not do this rounding and may be more appropriate to use if you need to take advantage of all 16 digits of accuracy that One+One maintains.

Trigonometric Functions

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The trigonometric functions are sensitive to the angle mode: degrees, radians, or grads (deg, rad, or grd in the display where 360 degrees = 2 pi radians = 400 grads).

Set the angle mode using the Preferences dialog (available from the Display menu) or via the angle function. Except for atan2, these functions operate on the value in the x register and replace it with the function result (f(x)).

Key Function Description Type
sin Sine unary
cos Cosine unary
tan Tangent unary
acos Arccosine unary
asin Arcsine unary
atan Arctangent unary
  atan2 Two argument arctangent: same as atan(y/x) but in the correct quadrant binary
  sinh Hyperbolic sine unary
  cosh Hyperbolic cosine unary
  tanh Hyperbolic tangent unary
  asinh Hyperbolic arcsine unary
  acosh Hyperbolic arccosine unary
  atanh Hyperbolic arctangent unary
pi The value of pi (3.14159...)  
  deg Radians to degrees conversion unary
  rad Degrees to radians conversion unary

Binary Functions

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Plus 10 + 5.3 15.30
Minus 10 - 5.3 4.70
Times 1.6 * 3 4.80
Divide 22 / 7 3.14
Percent change from y to x: 100*(x-y)/y 50 %ch 60 20.00
y to the x power 25 32.00

Percent Functions

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Percentage (5% of 150) 7.50
Ratio (200 is 115% of what?) 173.91
Add on (5% add-on to 20) 21.00
Discount (5% discount on 20) 19.00

Repeated Operations

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One+One automatically remembers the last operation and value performed. Subsequent presses on the equals key will apply this operation to the current value in the display. For instance, to multiply a series of numbers by 1.5 type


Time Functions

One+One has three time functions

Polar Coordinates

One+One provides two functions to convert back and forth between Cartesian (rectangular) coordinates and polar coordinates. The relationship between polar coordinates and Cartesian coordinates is defined by the following picture and formula

x = R cos(theta)
y = R sin(theta)
R = sqrt(x2 + y2)
theta = atan2(y,x)
Key Function Description
R->P Convert from Cartesian coordinates to polar coordinates
P->R Convert from polar coordinates to Cartesian coordinates

Use the function to view the results and the function to separate the values during entry. For example, to convert the polar value R = 5, theta = 30 degrees to cartesian coordinates enter (making sure the calculator is in mode):

30 5

To view the results (x = 4.33, y = 2.5) use the key.

Number Base Functions

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One+One can display and compute with numbers in hexadecimal (base 16), octal (base 8), and binary (base 2) format as well as the default decimal (base 10) format. Non-decimal values are displayed with a subscript following them indicating the number base.

hexadecimal display
octal display
binary display

The functions , , , and convert values between bases and set the number base for further calculations and input. Use any combination of the numeric buttons and Graffiti to input non-decimal numbers. You must use graffiti to input the hexadecimal characters A through F since no buttons exist on the calculator for them.

Convert x register to hexadecimal number base. Range: Integers between 0 and 248-1
Convert x register to octal number base. Range: Integers between 0 and 236-1
Convert x register to binary number base. Range: Integers between 0 and 212-1
Convert x register to decimal number base. Range: Real numbers up to ±9.999999999x1099

Binary AND hex 7E and 5 4 hex
Binary OR hex 7E or 5 7F hex
Binary XOR hex 7E xor 5 7B hex

Values outside the range of each number base are wrapped (that is, the excess most significant bits are dropped) and are converted to an integer. The AND, OR and XOR functions are in the f(x) pop-up list.

Modular Functions

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A few functions behave differently when a non-decimal number base is chosen:

Two's complement. Replace x register with its two's complement (all bits inverted and 1 added)
Modular addition. Same as regular addition except that results that exceed the range of the calculator are wrapped.
Modular subtraction. Same as regular subtraction except that negative results are returned as two's complement numbers.
Modular multiplication. Same as regular multiplication except that results that exceed the range of the calculator are wrapped.
Modular division. Same as regular division except that results that exceed the range of the calculator are wrapped and any fractional remainder is discarded.

The other functions on the calculator can be applied to non-decimal numbers. However, if the result is not an integer that is in range, an error is displayed and the number base reverts to decimal. The value in the x register will be the result of the computation. Simply reapply the conversion routine to wrap and truncate the value to be in range.

Financial Functions

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The financial functions are governed by the equation,

PV*(1+i)N + PMT/i*((1+i)N-1) + FV = 0

This equation is used when the annuity mode (BEGIN/END preference) is set to ordinary annuity (payments due at the end of the period ). When the annuity mode is annuity due (payments due at the beginning of the period ) then PMT in this equation is modified to be PMT * (1 + i).

The financial functions have two modes: input mode and calculation mode. One+One is in input mode if a number has been keyed into the calculator or any non-financial functions have been executed. Executing one of the main financial functions (, , , , or ) stores the result of any pending operations (as if you had pressed ) in the associated financial register. One+One is in calculation mode after any financial functions have been executed or when there is a pending binary operation. The result of a financial computation is placed into the display.

Most of the time this should behave as you would expect. However, if for some reason One+One stores a value when you intended to compute one, simply execute the financial function again to obtain the desired result.

Number of periods Input mode: Store displayed value as N.

Calculation mode: Compute N.

Interest rate per period Input mode: Store displayed value as i (in percent).

Calculation mode: Solve for i. If the solver doesn't converge an error '-e-' will be displayed.

Payment per period Input mode: Store displayed value as PMT.

Calculation mode: Compute PMT.

Present value Input mode: Store displayed value as PV.

Calculation mode: Compute PV.

Future value (or balloon) Input mode: Store displayed value as FV.

Calculation mode: Compute FV.

Toggle between beginning of payment period (annuity due) and end of payment period (ordinary annuity)
Clear financial registers and set payment period to the end (ordinary annuity).

The sign of PMT and FV is dependent on the state of the cash flow convention preference. When you are not using the cash flow convention, the label for PMT and FV are followed by an asterisk: PMT*, FV*.

Cash Flow Convention

Financial problems can be thought of as a series of cash flows. For example a mortgage consists of a large positive cash flow (the loan amount) followed by a series of monthly negative cash flows (the payments) with possibly a final negative cash flow at the end (the balloon payment). The diagram below illustrates this situation.

Positive cash flows (amounts you receive) are shown as upward pointing arrows. Negative cash flows (amounts you pay) are shown as downward pointing arrows. The horizontal axis of the diagram is time, with time increasing to the right. The time between the equally spaced payments is called the period.

For the problem to be solvable with One+One, there must be at least one cash flow in each direction. It is always possible to add a present value or future value cash flow to meet this requirement. Think about your problem to determine which is more appropriate (see example 4 below).

Example 1: Suppose you are interested in determining the payment for a car loan of $18,500 at 7.25% interest for 5 years. The key strokes to solve this problem using One+One are

  1. to reset the financial registers (since the values in the registers are maintained between sessions with One+One it is a good idea to reset the financial registers before each use of the financial functions).
  2. to set the number of periods (in months)
  3. since the interest per month is 7.25/12 %
  4. to set the principal or present value of the loan
  5. to compute the payment per period (ans: $368.51)

Example 2: What is the payment if you are willing to pay a balloon payment of $2,000 at the end of the loan?

  1. Set the value $-2,000 as the FV (balloon) for the loan. The value is negative because this is money you will pay out.
  2. to compute the payment per period (ans: $-340.75)

Example 3: How much interest do you end up paying with the balloon payment?

  1. to compute the total payments minus the loan value (ans: $-3,945.17).

Example 4: To compute the effective interest rate in an IRA account that you put $2000 into each year, you will need to enter the current value of the account as a positive future value (FV) even though you haven't sold the assets in the account. To make the example concrete, suppose that you started your IRA in 1985 with a $10,000 rollover and that the value in the account is $80,000 in the year 2001.

  1. to reset the financial registers
  2. to set the number of periods (in years)
  3. to set the starting value of the account. The value is negative since you added this value to the account with the rollover.
  4. to set the annual contribution.
  5. to set the current value of the account. The value is positive since this is the money you would receive if you sold all the assets in the account.
  6. to compute the effective annual rate of return in the account (ans: 6.39%)

Statistical Functions

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The statistical functions accumulate sums based on the values in the x and y registers. These sums are used to compute the mean and standard deviation or can be accessed directly via and . Use to reset all the statistical registers to zero before accumulating sums. If you make a mistake keying in the x,y values and after pressing , re-key the errant values and press to remove them from the sums. The mean and standard deviation are computed as

with similar equations holding for the y component as well.

To do one dimensional statistics, type in the x values followed by the accumulate key . After you have keyed in all the values, computing the mean via or standard deviation will update the display with the result.

To do two dimensional statistics, type y x and then the accumulate key . One+One will compute the mean and standard deviation for both x and y when you press or . To view the statistical result for the y values, use to swap the values in the display.

Accumulate x,y
Remove x,y
Separate values
Standard deviation
Clear statistical registers
Swap x and y registers.

Legal Stuff

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Although care has been taken to insure a bug-free program, Creative Creek, LLC makes no warranty whatsoever, either implied or expressed, as to the correct functioning of this software. When using this software, the user assumes all responsibility for any damages caused, directly or indirectly, by its use.

One+One is copyrighted. Copyright laws apply and the software shall be classified as proprietary material. The unregistered version may be given to your friends. If you want to include One+One on your web site or to distribute it in any way, please contact us at our contact page.

When you purchase One+One you are granted a non-exclusive, non-transferable license to use the software and documentation for use in accordance with this License. This License allows use of the software by a single user unless otherwise specified by the description provided at time of purchase.

One+One, One Plus One, and Creative Creek are trademarks of Creative Creek, LLC. Palm, Palm OS, and HotSync are trademarks of Palm, Inc. or its subsidiaries.

Contacting Creative Creek

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See the Creative Creek web site for up-to-date information about One+One.

If you have questions, suggestions, bug reports, or you just want to tell us how you much you like One+One you can contact us on the web at http://www.creativecreek.com.


Copyright © 1999-2007 by Creative Creek, LLC and Clay M. Thompson -- All rights reserved.

Last updated: 10-May-2007