Do I need to create an instance of class to be tested with unittest?

Say I have:

class Calculator():
    def divide (self, divident, divisor):
        return divident/divisor`

And I want to test its divide method using Python 3.4 unittest module.

Does my code have to have instantiation of class to be able to test it? Ie, is the setUp method needed in the following test class:

class TestCalculator(unittest.TestCase):
    def setUp(self):
        self.calc = src.calculator.Calculator()
    def test_divide_by_zero(self):
        self.assertRaises(ZeroDivisionError, self.calc(0, 1))