Unlike the Persian alphabet, Persian numbers are written from left to right. Basic numbers in Persian are as follows:

It is noteworthy that the origin of this system is Indian. In the numbers shown above we can see that both Persian and English numbers share the same origin. In English this system is called the Arabic system. See how between Latin and Persian numbers “۱, ۹, ۰” look very close; and how “2” “3” and “7” are only rotated “۲ ”, “۳ ” and “۷”, and so forth.

Names of these characters in Persian are as follows:

In Colloquial Persian the following conventions are observed:

The /h/ in cahār is dropped and the number is pronounced cār.

The /j/ in panj and the /t/ in haft and hašt are very weak; especially haft and hašt are normalized as haf and haš, especially before the counting word تا tā:

هچلهف
hacalhaf (or, hašt al-haft)
‘gibberish’

هفت تا مرد
haf tā mard
‘seven men’

هشت تا خونه
haš tā xune
‘eight houses’

Before vowels, in the colloquial dialect the /t/ may variably reappears:

هفت آسمون
haft āsemun or haf āsemun
‘the seven skies’

šeš is pronounced šiš.

The /h/ in noh disappears and the /o/ is lengthened; hence, /no:/.

The word for number is عدد adad (an Arabic loanword), with the broken plural اعداد a’dād.

Another word نمره nomré (plural, نمرات nómarāt, occasionally نمره ها ) is also used, more like the word ‘digit’ in English; but it also could mean ‘number’ and even ‘grade’, such as that made in an exam.

For instance ‘the room number’ is نمره ی اتاق while عددِ اتاق means something like ‘the number of rooms’ (‘…at a hotel…,’ for instance), in which the word عدد is more like ‘count(s) ’: دو عدد نان do adad nān ‘two counts of bread’ (i.e., ‘two loaves of bread’, or such).

An original Persian word as شماره šomāre ‘number’ is also used, which means both. For instance, “phone number” is شماره ی تلفن šomāre-ye telefon, occasionally نمره ی تلفن; but never عدد تلفن, which roughly could mean ‘the number of phones’. And, finally, π pi is عدد پی adad-e pi, not شماره ی پی or نمره ی پی.

Here is a chart with the first 20 ‘numbers’ a’dād اعداد spelled out: