When doing homework or taking important tests that require addition, division, etc., do I need to write the exact relat. at. mass number from periodic table or can I just write the whole number. For example do I need to write Fe as 55,85 or can I just write 56. Or for example do I need to write C as 12,01 or can I just write 12.

It is very messy and unconvenient to me to divide with decimals included, for example if I divide 16 by 44,01 it takes much longer to finish division and I multiply it by 100 to get a cleaner number 1600:4401 which is a mess to calculate.

If a test doesnt require you to write the answers/solutions manually, but instead you have to choose between a) b) c) d), then I guess using whole number for relative atomic mass is fine. But what about tests where you dont choose between a) b) c) or d), but where you must write answers manually.

Also I need to know if the solution was calculated using only whole-numbered relative atomic masses (ignoring decimals or rounding them), will it be accepted as a correct answer on a test?