A nursery owner buys 9 panes of glass to fix some damage to his greenhouse. The 9 panes cost $22.95. Unfortunately, he breaks 4 more panes while repairing the damage. What is the cost of another 4 panes of glass?
To get the price of one pane, you have to divide 22.95 by 9, so one pane is $2.55. Then you multiply the cost of one pane by the number of panes needed, which is 4.