Sir or mam is it compulsory to round off numbers in chemestry.like 35.6u i got so can we round off the ans to 36u is it ok mam or sir i want full explanatiom in a paper

Dear Student

It's not necessary to round off the value. In case of MCQs,  if the options are so (rounded off) then you can otherwise you can leave them as such.
Exact values are always good.

Regards