I asked my mom about this (high school from 1958-1962; I think she started school in 1950), and she said that, yes, they mostly used pencils in school, but ballpoint pens were definitely available and not uncommon. The only time she used a fountain pen was at home, and that was just playing with an old one to try it out. She grew up in a tiny rural town and had a frequently out-of-work father (he was a chronic alcoholic), so it wasn’t like she had more resources to work with, either.
Pencils are better for sticking in your ear.
newfangled number 2 pencils. we had chalk with a slate (with round corners).
yeah eraser, more friction so less slippage, makes a mark less dependent on good control.
I’ve gone back to using pencil for a different reason: they work. Maybe it’s the weather, but in the past I’ve gone through half a dozen pens before finding one that actually works.
Every college math professor/instructor up through maybe Calc IV or Advanced Calc reminded students either verbally or in the syllabus to use pencil, not pen for everything. Homework, tests, whatever. After that in math it was supposed to be understood, I guess.
I think pen looks ugly to people who have to grade things with a bunch of error/corrections in one-color ink.
FWIW I had the same complaint one of my first music theory classes in 7th grade – “My boy, I use a pen for a crossword…” Very avuncular – can’t remember what his wind-up was, but basically don’t use pen for writing scores until it’s ready to be inked.
Since music when I was a boy and college math (through basic Real Analysis, anyway), the pencil is far greater than a pen.
Elem teachers might have had similar training, or they’re just sick of looking at smudged ink with unclear indications of what’s the “real” answer and what’s not.
Hate those big fat kid pencils though – give me 0.5mm every time. Failing that, without my nice brass sharpener and a few of my favorite no2, I’ll take a gross of golf pencils everytime. Bic, disposable, 0.5. And lots of them.
I didnt read all the responses. I just wanted to say that I’m surprised things are still like that. I remember being a kid in 2nd grade (1992 I think) and I got a Christmas themed ink pen that was also a necklace, I thought it was pretty cool.
I got in trouble for using it on my worksheets at school. I’d totally forgotten that memory.
Eh, not really. Some people are happier that way, but I greatly prefer pens. I did all my math and computer science homework and tests in college in pen.
If pencil could actually be 100% erased, I might agree with you. But erasing always leaves some remnants, and sometimes chews up the paper. A simple line through a mistake is cleaner in my opinion. And if you make a bunch of errors, then toss the page and start over.
Remember those “erasable” ballpoint pens? What a cluster fuck they were.
I so incredibly disagree with you. Erasing is the worst concept to introduce to kids. They can’t learn from their mistakes if they can no longer see them. They should never erase- it wastes time and doesn’t ever appear “neat”. Simply cross out the word and write it again- paper isn’t expensive. Presentation should come after they master writing-- not simultaneously. (I’m sorry but this is one of the most frustrating things about school that I have encountered as a parent.) To put it as an analogy, did you learn to type first or did you just start writing code/novels? How about bicycling: did those cars stay 3 feet away while you were going down Main Street while you had your training wheels on? How many of your finger paintings are now in the Louvre? okay the last is a stretch, but they all demonstrate a logical process before you worry about “presentation” and in all cases legibility and communication need come first.
Once we started using pen, we also started using something called papel de sucio, “rough-work paper”. You ran any calculations that you didn’t need to show on that one.
We call that “scratch paper” in American English. 
This is similar to my opinion on the way “literature” is taught in school, and my ideas about why so many people “don’t like to read”. School teachers have kids diving right into Shakespeare and The Great Gatsby and Wuthering Heights and the other “classics” — things that middle school and high school kids really can’t relate to, in an attempt to teach them to love “literature”. To me, that ass-backwards. Teach them to enjoy reading first, by letting them read things that might actually interest them, and then introduce them to “literature”.