Test 3: Testing main.py output...
SUCCESS: main.py prints the correct message!
Output was: Calculator ready!
Test Add (5 + 3): 8
Test Subtract (10 - 4): 6
Test Multiply (6 * 7): 42
Test Divide (12 / 3): 4.0
Test Divide by Zero (10 / 0): Error: Division by zero
Main output test passed!