app.py

```python
# Simple Calculator Example
import math
import gradio as gr

def add(a, b):
    """Add two numbers"""
    return a + b

def subtract(a, b):
    """Subtract two numbers"""
    return a - b

def multiply(a, b):
    """Multiply two numbers"""
    return a * b

def divide(a, b):
    """Divide two numbers"""
    if b == 0:
        return "Error: Cannot divide by zero"
    return a / b

def calculator(num1, num2, operation):
    if operation == "Add":
        return add(num1, num2)
    elif operation == "Subtract":
        return subtract(num1, num2)
    elif operation == "Multiply":
        return multiply(num1, num2)
    elif operation == "Divide":
        return divide(num1, num2)

demo = gr.Interface(
    calculator,
    [
        gr.Number(label="Number 1"),
        gr.Number(label="Number 2"),
        gr.Radio(
            choices=["Add", "Subtract", "Multiply", "Divide"],
            label="Operation",
            type="value",
        ),
    ],
    "text",
    title="Simple Calculator",
    description="A simple calculator that performs basic arithmetic operations",
)

if __name__ == "__main__":
    demo.launch()
```