to display anything on LCD first it must be converted into ASCII
e.g. to display A you have to send its ASCII value 40h
to display a you have to send its ASCII value 63h
to display any number 0 to 9 send 30h to 39h
like wise
the given function first saparate all the digits of any number (eg 254 = 2, 5, 4)
then it converts all number into ASCII by adding 30h = 48 d