Jackson wants to paint a 3 foot border around the edge of the floor in his room. 14ft by 10ft. What area of the floor will remain unpainted?

Take the length of the outer rectangle, 14 ft, and subtract 3 ft twice. Then take the width of the outer rectangle, 10 ft, and subtract 3 ft twice. That will give you the length and width of the inner rectangle. Then multiply that length and width of the inner rectangle to find its area.

14*10=140 feet

140*3 = 420 feet