For fixed precision, you can either use an explicit format as Russell Adams points out, or you can modify (globally or per file) the variable org-calc-default-modes. That's a complicated variable and you only need to change one part of it for this:
(plist-put org-calc-default-modes 'calc-float-format '(fix 2)) See e.g. https://emacs.stackexchange.com/a/59181/14825 for some discussion. -- Nick "There are only two hard problems in computer science: cache invalidation, naming things, and off-by-one errors." -Martin Fowler