Calculate the Percent of Increase or Decrease of a Quantity: This lesson will teach students to understand a percent of increase and decrease as a change in area, from one initial to a final one. The concept is extended to word problems that involve the same concept. For these problems doing a sketch will help in the solution. You might find highly beneficial to have worked the problems before seeing the actual solution. If you got them right... you congratulate yourself, if not then you may find the solution more easy to understand and the long term learning takes hold more easily. Use the MARKER TOOLS menu pen and highlighter for that purpose.