We came across these numbers nesting boxes the other day when we were exploring West Elm's numbers rug and thought they'd be perfect for a child's room or to wrangle toys and gear in the living room.
They're made of cotton canvas and have handles for toting them easily around the house. The set of three costs $50 (currently on sale). There's also a large file box to match (17"w x 14"d x 11"h) for housing important documents, artwork or memorable schoolwork. Or nix the files idea and just use it as general storage. The numbers pattern box is on sale right now for $40 (as is the solid blue).