Question: how do I draw a ERD with cardinality? I am still in school and I am not sure how to go about it. I just need a sample idea Thanks

Answer: 
Depends on the notation you're using. I find that putting something like "0..\*" or "m" or "1" at one end of the relationship link, near the table it applies to, to denote "zero or more" or "m" or "exactly 1 required" communicates my intent pretty well.
Generally I like to use MS Visio(if you're a student you should be able to get it for free at [Dreamspark](https://www.dreamspark.com/).

Be sure to think about INSTANCE in ERD's instead of classes (I.E. an entity would be called Student, NOT Students).

Avoid many-to-many relationships as they don't make logical sense. instead use associative entities ([See here](http://www.wisegeek.com/what-are-associative-entities.htm)).

Start with only displaying maximum cardinality Student has many Grade and grades belong to one student:

```
(student)|---<(Grade)

```

Then get into Minimum cardinality Students don't have to have grades so Students have 0-Many Grades, but a grade MUST belong to a student so a Grade has 1 and only 1 Student

```
 (student)||---0<(Grade)

```

To read the above example you begin at the first entity, and identify the relationship. The entity is (student) and the relationship connects it to (Grade). Look at the cardinality markings on the OPPOSITE side that you started from. Since we started at (Student) we're looking at `0<`. Closest to grade is the MAXIMUM CARDINALITY, or the most (Grade)'s that a student can have. the `<` means a (Student) can have many (Grade)'s. The `0` is the Minimum CARDINALITY, and it tells us whether or not the relationship is required. in this case it's a `0` and not a `|` so it's not required