I deal with this DAILY. I operate a windshield repair business repairing chips, stars and running cracks in windshields. For running cracks when customers call I need details, mainly, how long is it?
I hear things like, "It's one inch."
My reply is, "So it's half the size of your little finger?"
"Oh no, it must be two inches."
I ask more questions and find out that what they have is really 30 inches long. I am amazed at the vast majority that have no concept or knowledge of measurement.
A few weeks ago, a customer asked me to measure her bedroom window. The blinds she purchased didn't fit (her brother had measured) and she didn't know how.
I've done work for public school teachers that don't know proper English (or at least they don't use it) or measurements. I don't understand how many of the college kids that I've done work for ever made it out of high school. So what the hell are they doing in college?
I think that a high school education 30-40 years ago had more practical value than many four year degrees today.
Metric? We learned it in school - there was talk about the US converting to metric. Glad we didn't - I know the math, but I can't think in terms of metric. The numbers are easier (unless you have a problem with decimals), but when you've learned to think and relate to our system, changing that would be difficult for me.