"The Feeling Of Power" is a short story by IsaacAsimov set in a world in which people have forgotten how to add and subtract, let alone perform more complex operations. They have computers that they use to do even the simplest of tasks. Thus they have forgotten many skills that we assume people should have, and lament that not enough do.
In this story comes a chap whose interest in antique machinery and native curiosity have got him to the point where he can actually do addition, subtraction and (gasp!) multiplication, all without using a computer. The story then follows his exploitation by the military and its results.
As with most Asimov, there's a good story idea and some attempt at characterization. Equally, the writing isn't great, but Asimov was and always will be a great page-turning author. This story is no exception.
Read it at http://downlode.org/Etext/power.html.
Oh oh, I forgot how to do long division on paper. If ever stuck on an island, I could not build a nuclear reactor like McGuyver and The Professor did for Gilligan.
Why is the story idea good? I find it rather silly.