The classroom can never have enough pencils. Every period at least one student doesn't have/can't find/dog ate their pencil. I used to fuss at them but it never really helped the situation. Then one day I overheard a kid talking about how he couldn't wait to upgrade his cell phone and my idea for free upgrades was born. I keep a stash of brand new pencils with perfect erasers. When a student tells me they don't have a pencil, I take a perfect one from my stash. The pencil-less student is momentarily excited, thinking he is going to get a perfect new pencil. But that wouldn't be fair, would it. Instead I tell the class I am offering a free upgrade and I let someone with a shabby pencil with a worn down eraser trade it in for a sparkly new pencil. Then the pencil-less student gets the traded in version. Everyone wins- kids who bring supplies are rewarded with a new pencil and the students have an incentive to bring their pencils because they never know when I will offer an upgrade special. My middle schoolers love it and they often ask if I have any upgrades available.