Final answer:
Mrs. Day instructs Pam and Mary Jo on woodworking, guiding them through marking, sawing, gluing, and clamping wooden pieces together.
Step-by-step explanation:
The best summary of the story provided is that Mrs. Day is helping Pam and Mary Jo make things out of wood. The girls are shown how to mark lines on the wooden boards, saw the pieces out, use glue to assemble the pieces, and then use clamps to hold the pieces together until the glue sets. The use of hammers and nails is not mentioned, and there's no indication that the setting is a day camp, which eliminates the other options provided as summaries.