Class credits?

<p>I was looking through class description and saw this:</p>

<p>"(Two credits given if taken after Math 1A/10A )". What does "two credits" mean ?
Does this mean that taking this class won't fulfill my GE requirement?</p>

<p>This was probably for MATH 20A. Generally, all the classes in both the 20 and 10 series are worth 4 units each but if you take classes from the lower series (10) and then decide to switch into the more rigorous one (20) you have to repeat the last class you took in the 10 series for 2 units. All of the classes in both series will give you 4 units unless you are switching from 10 to 20 or you have AP credits</p>