I asked my cousin what I should bring for him and the family next time I travel to Cuba. The reply is interesting [my translation]:
“I think the most important are pencils to write. We have pencils here in Cuba, but, I'm not lying, they are so bad and old -- graphite that has rotted (I guess without exaggeration that pencils are still the Russian season) and to sharpen them twice, the whole pencil disintegrates.
We also need erasers, but not as many as you sent last time. Last time, we gave erasers to our son to take to school. You gave us large erasers and the ones that fit on a pencil. He lost (or gave away) several erasers. We punished him strongly.
Now, we attach the erasers on a string of thread for him to wear on his neck. When he comes home, we inspect that he has not misplaced the eraser. Since he no longer loses them, we only need two or three more for the school year. “