SHIFTIN/SHIFTOUT are commands that will change the TRIS on the fly as needed, so I just set the TRIS as 00000000 and let PBP take care of it.

this works better and is alot more acurate since it does the math with large numbers and then reduces it.
however this is the code I use for converting a ADC line not if i have the Celcius number to begin with
So what does */461 do?
How do you know if one is better than the other if you do not understand how one of them work?

Look in the PBP manual chapter 4 if you are using pre PBP3, chapter 3 if you are using PBP3. It does a good job of explaining it.