A circle equals 360 degrees. There are 12, 5 minute sections on a clock. Divide 360 by 12 and you get 30.
If you move the hour hand backwards from 6 and move it to 2, you will move the hour hand 4 times.
Since 360/12=30, you will multiple 4 by 30, and you will get an answer of 120 degrees.
Here’s how it will look:
360/12=30
30*4=120 degrees