How to dispose my kids textbooks?

I was going thru our ‘kabans’ when i saw that Ate Mona is still keeping my kids’ textbooks from the past school years.

I have 2 kids (soon 3 kids) going to school, each school year, they’ll probably have 7+ books, not to mention notebooks etc. So we have like 30 textbooks each year to throw away.

So how to dispose them at the end of school year?
* I cannot give them away because they’re already used. They put answers on them. Or are there willing to still have these used books?
* Maybe to the junkyard / recycling shops.
* maybe schools can take them back, then give them back to the publishing house so they can recycle it.