Verbal Numerals

The X-Number structured number-entry procedure is based in the usage of Verbal Numerals.  A verbal numeral is the representation of a number by using a sequence of digits and structures.  In the decimal system, numbers are actually combinations of digits and numerical structures, where numerical structures are the main multiples of ten that had been assigned a single word in a given language.  Most of the modern languages have a word to represent these structures.  In English, for example, the 100 structure is called "Hundred," the 1,000 structure is called "Thousand," and the 1,000,000 structure is called "Million."  In Japanese and other Asian languages, 10,000 is a numerical structure.

If a symbol is used to represent a numerical structure, then a number can be represented by a sequence of numbers and numerical structures arranged in the same way as the number is pronounced verbally.  This is called a Verbal Numeral.  Lets say for example, that we use the symbols "H", "T", and "M" to represent the structures "Hundred," "Thousand," and "Million."  Then numbers can be represented as shown in the following examples:

Notice that, in most of the cases, the number of symbols required to represent a number is smaller when the Verbal Numeral representation is used.

US Patent 5,623,433 describes the concept of the Verbal Numerals and covers the algorithms used to convert Verbal Numerals into Decimal Numerals and vice-versa.

Extended Numerical Keyboard

By using the concept of the Verbal Numerals, it is possible to design a 13-key numerical keyboard that allows entering a number in a  way similar to its verbal expression. 

In the following examples, [H] represents the hundred or 00 key,  [T] is the thousand or 000 key, and [M] is the million or 6x0 key.

For example, to enter the number "Two million forty seven" you may enter the sequence [2][M][4][7].

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 requires less number of keystrokes. 

Discover why "One thousand one hundred" [T][H] is different from "One hundred thousand" [H][T].

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

The keyboard may detect automatically the input procedure (traditional or structured) that a user is applying at a given time.

The structure keys can also be represented as: [00], [000], and [6x0], which stand for “Hundred”, “Thousand” and “Million” (to make them language independent).  

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.

Another advantage of using a 13-key design is that it reduces the average number of keystrokes required to enter a number when the number contain zeroes.   Note 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.

Finally, note 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.   A 13-key device allows mixing both methods during the same number-entry operation.