British and American most common term for rubber/eraser shavings
Solution 1:
I prefer "eraser crumbs".
(In the US a "rubber" is something else entirely.)
I was going to add an Ngram comparing "eraser crumbs" to "eraser leftovers", but Ngram found no instances of "eraser leftovers" or "eraser debris" at all in its database.
I can show you this one, though
LINK
Solution 2:
One term is "eraser rubbings".
For example the 1915 British book Surveying & field work: a practical text-book on surveying says:
Keep the plan as clean as possible, by covering up the portions that are not being worked upon, and see that there is no dust or eraser rubbings in the path of the drawing pen.
Gregg Typing: Techniques and Projects (1931, American):
Dust is the machine's greatest enemy, so see that the machine is covered when not in use, and be very careful not to allow eraser rubbings to drop into the type basket.
Ladies' Home Journal (1949, American):
Already the smell of education was in our nostrils: the combined aromas, odors, reeks and stinks of ink, tablet paper, pulverized carbon and pencil wood from overflowing pencil sharpeners, eraser rubbings, chalk dust, the newly silvered steam radiators the first time they were turned on.
Early Frost (1952, American):
...she found two envelopes. Scraps of eraser rubbings and pencil shavings clung to them. She brushed these off against her skirt...
Macworld: The Macintosh Magazine (1984, American) says:
No tiny eraser rubbings covering your desktop, no glue stuck to your fingers
There are many examples that I could list, but my favorite is definitely:
Little heaps of eraser rubbings are of no value to anyone and you may decide your original word or phrase was better after all
Orbis (1977, British)
Solution 3:
preamble,
OP has clarified that OP's foreign-language kids
are moving to UK/US and wonder what they should say to indicate these things:
The factual answer (to that question is) there's no such term. (It's inconceivable a kid would use rubbings, erasings, debris, crumbs, etc.)
Kids just say "the eraser stuff" or "the stuff that came off when I erased."
That's it.
OP, often with SWRs the correct and best answer is that in fact there is no such term in English.
Indeed, this is quite common among SWRs on the site.
It's important to realize that one can think of a good SWR to use for a given SWR puzzle, and that's a fun part of the game on the site. In the example at hand, one of the answers suggests "crumbs" and that's a fantastic/erudite idea, and I'd imagine that a handful of times someone has used that clever term.
(Indeed - it's a bit of a phenomenon in English, that certain fairly common things, actually annoyingly don't have words: so we use "whatsit" or "thingy" - indeed please review this astute question! )
So for this SWR in fact interestingly there is no common term.
That's the answer.
Everyone says "the little eraser thingies", "the purple bits that came off", "rubber bits", "eraser mess" etc.
The best you'll get are erudite/natty possibilities (the main purpose of this site after all!), or in some cases technical terms (cool to know, but not an answer to "the" currency word).
As a footnote, it occurred to me that: erasings works well. (I would probably use that if - for some astonishing reason - the issue had to be discussed extensively. Note that erasings (might as well call them that) physically include tiny bits of paper, lead, rubber, the blue ink from the rules, etc, they are not really "just bits of rubber", so for me "erasings" works.)
But please note that I only include "erasings" precisely as an example of the fact that, on all SWR questions, part of the sport is thinking up a really good word that "should" be the currency world. Erasings is not commonly used; I just "thought it up" purely on the basis: "since the answer is 'there is no such SWR' here's one I thought-up".