I am sure that there are many jobs where mental math makes a huge difference.
I manage a team of engineers, and though pretty much all of them are head and shoulders above me in their specialisation, they think I really know my stuff because I find errors in their work and zero-in on them on the fly. The skill that I have is doing rough approximations in my head. Then from experience: a factor-of-two difference is commonly confusing kg and lb, a factor of 10 - confusing kg and N, a factor of fifty—mistaking degrees and radians (usually in Excel, where radians are the default mesurement), etc… I get a LOT of mileage from this :). If they did the same, their already good work would be even better. And I imagine any calculation intensive job (finance, economics, science, business...) is similar.
If you don’t have to do these kinds of rough calculations many times a day I don’t see this as a worthwhile skill (you could simply ask Siri/WolframAlpha, for example), other than perhaps to consolidate one’s authority (if you really have to play that game).
I am sure that there are many jobs where mental math makes a huge difference.
I manage a team of engineers, and though pretty much all of them are head and shoulders above me in their specialisation, they think I really know my stuff because I find errors in their work and zero-in on them on the fly. The skill that I have is doing rough approximations in my head. Then from experience: a factor-of-two difference is commonly confusing kg and lb, a factor of 10 - confusing kg and N, a factor of fifty—mistaking degrees and radians (usually in Excel, where radians are the default mesurement), etc… I get a LOT of mileage from this :). If they did the same, their already good work would be even better. And I imagine any calculation intensive job (finance, economics, science, business...) is similar.
If you don’t have to do these kinds of rough calculations many times a day I don’t see this as a worthwhile skill (you could simply ask Siri/WolframAlpha, for example), other than perhaps to consolidate one’s authority (if you really have to play that game).