According to a popular tradition, still tough in Egypt and North Africa, the “Arab” figures would be the invention of a glazier geometrician originating in the Maghreb, which would have imagined to give to the nine significant figures an evocative form depending on the number of the angles contained in the drawing of each one of them: an angle for the graphics of figure 1, two angles for figure 2, three angles for the 3, and so on:

We will have the following format:

This remained after nine and zero as they are. Make turn around eight, six, five, four, three and one. Reverse number two and the figure of seven. The delivery of some of these forms to each other, without change in the arrangement, we get this form:

This is an Arabic sentence meaning: My goal is calculation (æåÏóÝí ÍÓÇÈú) in Kufi line (This name called on all lines, which tend to location and engineering). With that zero is the stillness.

In this ancient manuscript, we find the number two of its original form.

To return at Alphabetic numerals Abjad we find that seven letters of this sentence æåÏóÝí ÍÓÇÈú is units in the table of Abjad numerals
(The Abjad numerals are a decimal numeral system which was used in the Arabic-speaking world prior to the use of the Arabic numerals). This is not a coincidence. Since the Abjad numerals were often employed to record the history of the events, the value of the sentence æåÏóÝí ÍÓÇÈú is the date of the invention of these figures.
6+5+4+80+10+8+60+1+2 is 176. 176 hijri is 792, history very appropriate to put these figures.

Source(s):
http://lescorpiondechair.ifrance.com/suj...
http://en.wikipedia.org/wiki/abjad_numer...
http://ar.wikipedia.org/wiki/%d8%b1%d9%8...