Connect the dots
Connect the dots (also known as dot to dot or join the dots) is a form of puzzle containing a sequence of numbered dots. When a line is drawn connecting the dots the outline of an object is revealed. The puzzles frequently contain simple line art to enhance the image created or to assist in rendering a complex section of the image. Connect the dots puzzles are generally created for children. The use of numbers can be replaced with letters or other symbols.
In adult discourse the phrase "connect the dots" can be used as a metaphor to illustrate an ability (or inability) to associate one idea with another, to find the "big picture", or salient feature, in a mass of data.
The travelling salesman problem asks what numbers to assign to a set of points to minimize the length of the drawing.