If you are adding fraction why have a decimal answer?!?

3/4 + 3/8 + 11/2

Obviously, 8 works well enough here.

2*3/2*4 + 3/8 + 4*11/4*2

6/8 + 3/8 + 44/8

=** 53/8**

======( which is 6.625 of course.) ( In college and in most math courses there, save statistics, you will be required to be exact and fractions are exact. )