"Did you put the whole library in your backpack?" I called down.

Darby squinted up at me. What little afternoon sunlight was left glinted off her glasses. "Mrs. Bonham says smart fourth graders learn long division while they're in third grade." She adjusted her straps over her thin shoulders with a grimace. "I think Mrs. Bonham should be arrested."

I bit back a laugh and jerked my head for her to come up. "Let's go to the snack machine so you can smear Cheetos all ...