I’m completely stuck on step 6 on the Cumulative Project 3 exercise.

This is the instruction:

```
Use Math.random() to generate a random decimal value.
All Java objects have access to the built-in `Math` object.
And `Math` provides a method named `random()` which returns a randomly chosen `double` value greater than or equal to 0, but less than 1.
For example, some possible return values are `0.2312` , `0` , or `0.999999` .
Call `Math.random()` within `generateRandomNumber()` and save it to a local variable.
```

This is what I did:

```
public class MainActivity {
public int generateRandomNumber(int max){
double value = Math.random();
return (int)value;
}
}
```

And this is the error message I get back:

```
Error: Main method not found in class MainActivity, please define the main method as:
public static void main(String[] args)
or a JavaFX application class must extend javafx.application.Application
```

Am I doing something really stupid?