Hi - I am a newbie LOL

I'm stuck on a project here

And, not sure if this was discussed before and pardon me if it was discussed before

I have Employee table with the following fields:

Name Null? Type
----------------------------------------- -------- ----------------------------
EMPLOYEE_ID NOT NULL NUMBER(4)
FIRST_NAME NOT NULL VARCHAR2(15)
MIDDLE_INITIAL VARCHAR2(1)
LAST_NAME NOT NULL VARCHAR2(15)
SEX NOT NULL CHAR(1)
MANAGER_ID NUMBER(4)
HIRE_DATE DATE
SALARY NUMBER(7,2)
COMMISSION NUMBER(7,2)
JOB_CODE NUMBER(2)
DOB DATE

Need to create a function called AGE to calculate an age (integer) based on Birthdate (DOB). I would appreciate if anyone here in this forum can help.