500
Peter weighs 156 pounds, but he would like to wrestle in a lower weight class. He loses 4 pounds one week, gains back 2 pounds the next week, loses 5 pounds the third week, and loses 3 pounds the fourth week. Write an addition expression to represent this situation. Then find the sum.
What is "156 + (- 4) + 2 + (- 5) + (- 3) = 146"?