Look at all the boxes and discuss their size. Ask children what they think might go in this box. Some boxes, like a shoe box, may be easy to determine. A tie box might be harder. Next take from bag all the items that need to be boxed.
Problem solve with the children until all the items have a box for mailing.
Write labels for mailing packages. Provide grocery boxes such as spaghetti, cereal, rice, egg cartons, and candy for matching, writing, and talking about. Set up a wrapping shop where children choose paper, wrap gifts, estimate length of string needed for tying. Draw a map of the mail carrier's route. Draw houses or shops along the way.