Let’s warm up with a quick arithmetic problem, which I want you to do in your head.
What is one thousand plus forty?
Now add another thousand
And thirty more
Plus another thousand
And finally, add an additional ten.
What’s the answer? According to Dean Buonomano, in his excellent book Brain Bugs, the majority of people give an answer of five thousand, instead of the correct answer of 3100.
“Most of us can find a face in the crowd faster than we can come up with the answer to eight times seven. The truth is—to put it bluntly—we suck at numerical calculations… (Read more and view comments at Forbes)