TypeError: 'collections.OrderedDict' object is not callable

# The dictionary will look something like:
# {'Andrew Chalkley': ['jQuery Basics', 'Node.js Basics'],
#  'Kenneth Love': ['Python Basics', 'Python Collections']}
#
# Each key will be a Teacher and the value will be a list of courses.
#
# Your code goes below here.
def num_teachers(dic):
    counter = 0
    for teacher in dic:
        counter += 1
    return counter

def num_courses(dic):
    counter = 0
    for teacher in dic.values():
        counter += len(teacher)
    return counter            

def courses(dic):    
    listCourses = []
    for courses in dic.values():
        listCourses += courses
    return listCourses        

def most_courses(dic):
    max_courses = 0
    max_teacher = ''
    for teacher in dic:
        if max_courses < len(dic(teacher)):
            max_courses = len(dic(teacher))
            max_teacher = teacher
    return max_teacher