13.
You can write it as "13/16 in".
You could write it as -13/1.
It is not clear if your PhD is in English or you want to write a letter in English. If you want to write a letter in English you should ask this question: How do you write a letter in English asking for PhD supervision.
How do you write the number 04.05.1984 in English?
Well..Most Of Them...Or Me...Would Write About Global Warming...Or Mabye Anything That You Like Or Your Hobby...Depends On What Kind Of speech That Would Be....
There are millions of people on the planet who cannot read or write English !
we will write 100,500
13/1
.13
13 = thirteen.
Read read read read. And then write write write write.
How to write 2012 in letters