Polyomino puzzles use pieces made from connected square units. The picture gives a layout to explore as the pieces are compared and fitted together.
Notice how each piece is built
Look at the connected squares in a piece and trace its outside edge with your eyes. Then compare that outline with an open part of the layout. A corner or a longer side can be a useful place to begin looking.
Fit the pieces into the larger layout
As pieces meet, notice which edges line up and which spaces remain. If the child pauses, describe what is visible rather than supplying a solution: a gap, a corner, or a side that seems to match. The puzzle is a chance to look at the relationship between part and whole.
Compare with other picture mechanics
For a different way to work with forms, open the shape-matching or tangram guide. Picture puzzles use illustrated pieces instead of a connected geometric layout. The current App Store page gives the latest release and purchase information.