I worked in retail when we had a cash box for a "till" and did almost $2 million a year, mostly cash and checks, not much revolving credit, maybe 20% was VISA and what was it called then ... Oh, yeah, MasterCharge ... four sales staff, everything we sold was at a discount and you were giving ballpark figures all day. For a quote or a sale we'd use a calculator and make it to the penny, but even then, you had to know if the number was funny.
If you couldn't do math, you couldn't work in cash or retail, pure and simple. They'd fire you.
But that's not Algebra. All you needed was primary school Math, 6th grade stuff. It was a little before my time, by the time I was of age you needed a College Degree, but not my oldest sister's ... in the 60's IBM was still hiring High School grads. Her husband was teaching new hires with Electrical Engineering College Degrees at the Telephone company with his Gr12 Diploma.
Of course at least in Canada those 60's grads needed Latin to get a HS Diploma. I had a second language in HS but it wasn't mandatory by the time I went, although it was still mandatory to have a second language to get a College Degree. That's gone now too.
Kids today don't even know that; the till can give out a number that is pure Science Fiction and they just dole out the amount from the cash drawer, none the wiser.
I often wonder what they think of us old geezers who go, "No, that can't be right". My guess is they just think of us as people who hold up the line. I know that's what I would probably think to myself, putting on my teenage hat and remembering how it was to see the world as us and them.