Testing with manual calculation or programmed calculation?

I'm using Django and I need to write a test that requires calculation. Is it best practice to calculate the expected value manually or is it ok to do this by using the sum function (see below)

This example is easier for me because I don't have to calculate something manually:

def test_balance(self):
    amounts = [120.82, 90.23, 89.32, 193.92]
    for amount in amounts:
        self.mockedTransaction(amount=amount)
    total = Balance.total()

    self.assertEqual(total, sum(amounts))

Or in this example I have to calculate the expected value manually:

def test_balance(self):
    self.mockedTransaction(amount=120.82)
    self.mockedTransaction(amount=90.23)
    self.mockedTransaction(amount=89.32)
    self.mockedTransaction(amount=193.92)
    total = Balance.total()

    self.assertEqual(total, 494.29)