How to change all numbers in the iphone from indian to arabic numbers without changing the "region format " ?

How to change the indian numbers (١،٢،٣،.....٩)to arabic numbers(1,2,3,...9) on the iphone without changing the "region format " (settings>general>international>region format)?.

I living in UAE (United Arab Emirates) so i choose that country as my region format but the problem is every time i choose that country all the numbers on my iphone become indian numbers such as calendar , contacts , time and others however if change the region format to USA or UK all the numbers become arabic numbers (1,2,3,....9) why is that ? I do not know

So could any one help me please ?