I ve been wondering lately.... In my physics studies at university one of the most important things was to always use units as it also gave you a sense of whats going on and if things are correct. Now in finance i ve never really seen this. For example conversion rates should have the unit \[$/€\] or inflation \[€(today)/€(last year)\]. Why isnt this more a thing? Whats interesting is that P/E ratio has the unit \[€/(€/year)\]=\[year\].