The science and technology class is studying robotics. One group builds a robot that can be controlled by entering positive and negative numbers into a control unit. Negative numbers make the robot roll backwards a specific number of inches. Positive numbers make it move forward a certain number of inches. For example, if −5 is entered, then the robot moves backwards 5 inches. The students enter the numbers −37, +22, and −16. What number do they need to enter to make the robot return to its original position of 0?
