As someone who studied engineering: I always use a calculator because I learned over those years to NEVER ever trust my mind maths, even for basic stuff like 3x5
I trust my mind math if I need approximate and it’s not super important. My brain is really good at back of napkin math but if I needed the actual answer or otherwise need precision, I’m pulling the calculator out. If I want to know where a falling object is roughly going to land, I’m good but if I need to know how much wood I need for a project, I should do the work of making the drawing and manually add it all up with the calculator
As someone who studied engineering: I always use a calculator because I learned over those years to NEVER ever trust my mind maths, even for basic stuff like 3x5
I trust my mind math if I need approximate and it’s not super important. My brain is really good at back of napkin math but if I needed the actual answer or otherwise need precision, I’m pulling the calculator out. If I want to know where a falling object is roughly going to land, I’m good but if I need to know how much wood I need for a project, I should do the work of making the drawing and manually add it all up with the calculator