Page "Light Up" Paragraph 3

A typical starting point in the solution of a Light Up puzzle is to find a black cell with a 4, or a cell with a smaller number that is blocked on one or more sides ( for example, a 3 against a wall or a 2 in a corner ) and therefore has only one configuration of surrounding bulbs.

After this step, other numbered cells may be illuminated on one or more sides, narrowing down the possible bulb configurations around them, and in some cases making only one configuration possible.