Math 180 Calculus for Business and Social Sciences is a four-unit transfer-level class, transferrable to the UCs, CSUs, and many private universities.
Math 180 Calculus for Business and Social Sciences with Corequisite Support is two classes/CRNs: the four-unit transfer-level Math 180 Calculus for Business and Social Sciences class and a two-unit Math 080 Corequisite Support class, which is basic skills (the corequisite support class is graded pass/no pass).
These two classes are linked so students must add both CRNs (course registration numbers) to their schedule. The classes are scheduled sequentially (next to each other).