If you watch videos online, you are probably using YouTube:

• Keys 0 through 9 skip through the video. Press 5 for 50%, 7 for 70%, etc.
  

• The J, K, and L keys also have useful functions.
  

• Press J to rewind, K to pause, and L to fast forward. These keys only work in this manner when the video is paused.
  

Watch Videos The Easy Way!