I do arithmetic in my head whenever I can spare the extra seconds
Same, except since I can almost always spare the extra seconds, my condition is “when I can afford to be as likely to make a mistake as I believe that I am.”
Although more frequently I just don’t have a calculator handy.
Same, except since I can almost always spare the extra seconds, my condition is “when I can afford to be as likely to make a mistake as I believe that I am.”
Although more frequently I just don’t have a calculator handy.