[Q]: Objective: Clean gunk from pools.
[A]: Float a few tennis balls on the surface.

[Q]: Objective: Make use of post-its before you throw them away.
[A]: Run them between the keys on your keyboard to collect crumbs and fluff.

[Q]: Objective: a jar
[A]: can hold paint effectively

[Q]: Objective: How to make a chain from construction paper.
[A]:
Cut about 15 strips of construction paper 1 inch wide and 10 inches long. Make your first strip of construction paper into a ring and glue it together. Slide your next strip of construction paper through the ring and glue it into a ring. Repeat the process until you have a long chain of construction paper rings.