Gas Law question?

Question

When a question uses charles law, and wants you to find the temperature, but asks for it in Celsius temperature,
((it gives the volume in liters and one temperature in celsius))
Do I convert the temperature to Kelvin to do the calculations and then subtract 273.15 to get Celsius, or do I just use the temperature it gives in Celsius to do the calculations? Because i tried it both ways and got a different answer.
Here is the question:
Use charles law to find T1:
V1= 146 L V2= 89 L T2= 132degrees C
answer in units of degrees C.
Charle's law is V1T2=V2T1
I converted T2 to K (405) and then i just subtracted 273.15 at the end to get the temperature of 391.232 C
If i do it with Celsius from the beginning, i get 216.539 C.
Which is correct?

Answer 1

Yes, all calculations with gas laws require that the temperature be in an absolute scale, ie, one that starts out at 0: either Kelvin, or Rankine (is you're using U.S. units).

Answer 2

All temps must be in degrees Kelvin. Then if you want to convert at the end that is fine.

Answer 3

you have to convert to kalvins first or ur answer will b wrong