Extended Numerical Keyboard with
Structured Data-Entry Capabilities

US Patent # 53,456,765

The method covered by this patent allows the implementation of a 13-key numerical keyboard.

With this keyboard, you can enter a number in the same way as you pronounce it verbally.  For example, to write the number "Two million forty seven" please enter the sequence [2][6x0][4][7] in the keyboard at the left.

Of course you can still enter it as [2][0][0][0][0][4][7] which is the traditional procedure, but the structured entry mode is more natural and usually requires less number of keystrokes. 

Discover why "One thousand one hundred" [000][00] is different from "One hundred thousand" [00][000].

Did you know that the number "One thousand seven hundred thousand" [000][7][00][000] does not exist?

The [swap] key allows to change the mode between [] structured and () standard in the middle of a data entry operation. See the difference between [1][0][0][0][5] and [1][0][0][0][swap][5].


Sundstrand 10-Key KeyboardIn 1914, Oscar J. Sundstrand of Rockford, Illinois, founder of the Sundstrand Adding Machine Co. introduced the 10-key numerical keyboard arranged with three rows of digits: [7, 8, 9] [4, 5, 6] [1, 2, 3] plus a zero key.

CANON P200-DH KeyboardWhen electronic calculators appeared at the beginning of the 1970’s, the same 10-key keyboard designed under mechanical limitations was maintained. Some desktop calculators added a double-zero [00] key, and even a triple-zero [000] key with the purpose of making it easier to enter some numbers, but this was just a shortcut intended to avoid pressing the [0] key two or three times.

TI-83 PusSince then, electronic calculators have evolved in many different ways,   displays changed from LED’s to LCD’s; hundreds of business and scientific functions have been added,  and every imaginable combination of shapes, material and colors has been used.  However, the basic 10-key design has not changed since its inception

The 13-key design

Extended Numerical KeyboardThe  US Patent # 53,456,765 covers two algorithms that activates  three structure keys converting the standard 10-key numerical keyboard into a 13-key keyboard.

The structure keys are: [00], [000], and [6x0], which stand for “Hundred”, “Thousand” and “Million” (to make them language independent).  Using these keys, a user can enter a number by pressing the keys for the words used to pronounce the number in most western languages. Because of this verbal approach, the user does not have to convert mentally the number into a sequence of digits prior to typing it into the keyboard.

A second advantage of using a 13-key design is that it reduces the average number of keystrokes required to enter a number.   Notice that in the first example provided above, to enter the number 2000047, the 13-key design required only 4 keystrokes against the 7 required by a 10-key design.  This holds true for most large numbers.  This advantage is language independent and can be useful even in non-western languages such as Japanese and Chinese.

You should also notice that the X-Number method is an extension, not a replacement, to the functionality of the regular ten-key design.   Users can still use the traditional digit-by-digit method.   In fact, a 13-key device allows mixing both methods during the same number-entry operation at user’s convenience.


The X-Number 13-key design can be used  among other areas in the following applications:

SHARP EL-334 ABElectronic calculators.  Since its beginnings, early in the 1970’s, the market of pocket calculators has been very competitive.    At the end of the calculator wars, basically two types of calculators have survived:  Specialized business or scientific calculators made by large companies such as Casio, Texas Instruments Sharp, and Hewlett Packard, and regular four-function calculators made by a very wide range of companies.   In this second category, the competition is not based in functionality since all of them do exactly the same thing, but instead it is based on appearance such as display size, colors, shape, device texture and materials.  I personally believe that it is in this category where there is a lot of room for the usage of the 13-key design.  A change in the keyboard design, in addition of improving its usefulness by making it easier to enter numbers, could tap into the “novelty” factor of the market (users attracted to something new that has never been seen before.)

Microsoft Windows CalculatorPC Software Calculators. A variation of the HEXACALC calculator written by the famous Windows programmer and author Charles Petzold has been included by Microsoft as a Windows accessory since the introduction of Windows 95. The use of a mouse to click on the keys of a software calculator is highly inconvenient, especially when the number of digits is relatively large (which is usually the case when you have to resort to the use of a calculator). This is another area where the reduction in the number of keystrokes provided by a 13-key design can be particularly useful. Currently, I'm in the process of writing a Windows calculator in Visual C++ that will have this functionality (plus other ideas I have about the design of a software calculator).

X-Number On-Line CalculatorOn-line Internet Calculators.  This Web site provides several examples of On-line calculators.  I have written all of them in Java Script so that the source code could be easily reviewed and accessible, however, they can be implemented in other languages such as Java and Active-X. There is no license fee required for the usage of this Java Script code if the web site has no commercial objectives. Just send me a note advising that you are using the code or the algorithms.

Palm XCALC ColorHand-held Computing Devices. The success of Palm Computing (whose income surpassed in 1999 the one of its parent company 3Com) shows the importance of these type of devices. All of them include some kind of software calculator. As with the PC software calculators, the algorithms provided in the X-number patent could enhance its functionality.

Toy calculators. I've had the chance to show how to use the extended keys to enter numbers to children under the age of seven by using the calculator posted in my Web site. All were very exited when discovered how easy it was for them to enter large numbers that before they would even hardly know how to pronounce. Since then, I've been putting attention to toy calculators in the market, and found that there are very few of them. So far, the ones I found were just regular calculators made with colorful cases and packed as "toys." I believe that a toy calculator should be designed with some special functionality, which, in addition to using a 13-key very colorful keyboard, should include some kind of numerical game (like guess-and-enter-the-answer and return a right or wrong random sound) that would make its use enjoyable and educational for children.

PC Keyboards. If the usage of the structure keys becomes widely accepted, then, it will be the time to add these keys to the numerical keypads included in standard computer keyboards, the signals sent by the structure keys will then be processed by the X-Number algorithms to handle the processing of numerical data-entry operations.

Of course, the applications described above are just some examples of the possible application of this data-entry method.  In general, this method can be implemented in any device or application requiring intensive numerical data-entry operations.

If you are interested in obtaining a license to use this patent in your products or applications, please contact:

James Redin
312 16th Place
Manhattan Beach, CA 90266
(310) 545-8092

In Japan:

3-25-11-1003 Koyama Shinagawa
Tokyo Japan

Copyright James H. Redin. All rights reserved (1996-2003)

Mechanical Calculators    Old Electronic Calculators