Number translation with 118n module
You can use PersianTools modules,
Features

This module is going to cover some basic features required for Persian
websites.
Fix possible misplaced chars in mixed Persian and English texts
Find a way to fix Calendar.
Convert English numbers to Persian numbers.
Fix sort issues for persian characters.


One of its features is Convert English numbers to Persian numbers. ( indeed Persian number is Arabic digits ).
Install this module and go to its settings and just active convert digits.
Also you can convert all Latin digits to Arabic with some Js code.
Try something like this (put it in custom JS file and load in each page_
String.prototype.toIndiaDigits= function(){
  var id= ['list of arabic digits'];
 return this.replace(/[0-9]/g, function(w){
  return id[+w]
 });
}
var content= $('body').html();
$('body').html(content.toIndiaDigits());

See this articles about how change Latin digits to Arabic
https://stackoverflow.com/questions/1675786/convert-from-english-digits-to-arabic-ones-in-html-page
https://stackoverflow.com/questions/21415121/convert-english-digits-to-arabic-digits-in-html-documents
http://jsfiddle.net/McxL5/