How to make Lego Mindstorms EV3 robot go in reverse when move steering input comes from proximity sensor I saw an program on the Lego Education page which makes a Lego Mindstorms EV3 robot gradually slow down as it approaches a wall. The info from the proximity sensor is used as the direct wire input of the Move Steering block, the nearer the robot to the wall, the slower the speed of the robot. 

The problem is that my infrared sensor is on the rear of my robot (track3r). I would like to make the input to the Move Steering Block negative so that my robot motor moves backwards (in reverse) using this program. How do I do this? I can't make the output of the proximity sensor negative... can I?
Multiply the output of the proximity sensor by -1.