The main concept of innumeracy is the inability to
comprehend orders of magnitude -- to not be able to select the approximate
population of the earth when presented with these choices:
- 6,000
- 6,000,000
- 6,000,000,000
- 6,000,000,000,000
I did a little teaching and grading in
grad school, and it was sad to see the innumerate engineering students not only come up with an answer that was 5 orders of magnitude off, but to not realize that there was something horribly, utterly
wrong with it. It's not the initial error that's bad (I have come up with such horribly wrong answers myself at times -- I remember my senior group project where we, at first pass, came up with a tower 5 miles tall instead of 25 feet due to a unit conversion error -- but we, all of us, immediately recognized the answer as ridiculous and went back to find our error) but the inability to notice how impossible the number
is bad -- and that's innumeracy.
Part of the innumeracy problem is that with the prevalent use of calculators and computers today, people aren't taught to do any proper sort of estimation. Estimation is pointless to the innumerate, since they can't answer the question at the start of this writeup, so they will never think to learn it themselves either.