Another forgotten story from long ago:

Dan of HappyFunPundit tells the sad tale of a fast food clerk and her manager who couldn't subtract $14.72 from $20.00 without a cash register or calculator. The problem is not new.

In 1976 or so, when I was at the University of Chicago, I went to the college bookstore to buy some manila envelopes. The clerk (not a student, I hope) was unable to figure out the total cost of 12 envelopes priced at 5 cents each. She tried the cash register, but didn't have the patience to do it right, ringing up 5, 5, 5, 5, and 5, then 25, and only then realizing that she didn't know what to do next. She tried a calculator. She tried pencil and paper. The whole process must have taken at least ten minutes, though it seemed more like twenty. Like the several customers behind me in line, I was frozen in stunned vicarious embarrassment throughout. Eventually, she came up with a price of 80 cents, I agreed without hesitation, she rang it up, and the cash register added the appropriate tax automatically. Fortunately I had the exact change, so I paid and got the Hell out of there, wondering how she had ever graduated from high school. Of course, I soon realized that she would probably have been very grateful if I had told her the correct amount. Then again, perhaps she wouldn't have believed me.

I wonder whether she ever learned basic arithmetic, and whether she is currently employed. I don't imagine there are a lot of fields in which such gross arithmetical ineptitude would not be a handicap.