Argh!

How do I keep my calm with a near 10 year old girl who is impossibly sloppy and disorganized with everything that comes her way.
Jackets. Sweaters. Been through dozens. They all end up somewhere in a school yard, and never find their way back home. Or to Lost and Found for that matter.
She can't find a pencil sharpener or eraser on her desk if her life depended on it.
Practice sheets for french test? When she finally tells me they actually have a text (the day before), she forgets to bring it home.

I'm tearing my hair out!
Please, help me - what do I do???