Toothpick Squares
Six toothpicks are set up to form five squares. Move exactly two toothpicks to form four squares of the same size, without any toothpicks left over. That is, there shouldn't be any toothpicks that aren't part of a square, lying on top of another toothpick, etc.
More puzzles
Connect the Colors
Connect the colors without crossing lines.
Connect the Dots
Draw four straight lines, without lifting your imaginary pencil, that touch all nine dots in the grid.
Doorways
Travel through all the doorways exactly once.
Toothpick Equality
Add a single toothpick to form a mathematically true equality.