system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How do erasers erase?
gpt
Take a pencil and write on paper. What happens is the pencil "lead" (really a black carbon stick of something called 'graphite') scrapes off and sticks to the paper. It's pretty sticky so it stays and forms letters and drawings.

Now take an eraser to that pencill drawing. Paper was rough and the graphite stuck to it, but eraser materials is a lot stickier than that. So the stuck-on pencil graphite transfers off of the paper and on to the eraser. 

The eraser then wears away from contact with the paper and forms a little tiny plastic or gummy pill that contains the removed graphite, and that gets swept aside or blown off the page. The stickier the eraser, the better it removes and holds graphite, which is why newer white plastic-based erasers are awesome but old pink ones sometimes just make a huge mess.

**TL;DR: Eraser stuff is stickier than paper, so pencil stuff likes it better.**