Kotlin Math using Android Studio

Hello,
sorry my english,
this problem I only have on Android Studio, if I use only Kotlin with readLine or using numbers intead of editText (textField on Jetpack Compose) work’s here.
I trying to catch 2 fields of editText and multiply then, but, I try 4 diferent ways and not work.
This is my last try, just learn to use the “data class”, but, the same, open the emulator, put the numbers and when I press the button to “do the math”, the APP close.
I will put the kotlin LAST code I try here (on burnout mode):

data class Numeros(
var num1: String = findViewById(R.id.valor1).toString(),
var num2: String = findViewById(R.id.valor2).toString()
)
{

        var resultado = findViewById<TextView>(R.id.resultado)
        var calcular = findViewById<Button>(R.id.calcular)

        fun multi() = num1.toFloat() * num2.toFloat()
    }
    val res = Numeros()
    res.calcular.setOnClickListener {
        res.resultado.text = res.multi().toString()
    }

How do I do here?

You should get a stacktrace with that, which should help you understand why does your app close.

now I understud your reply.
The error is on function:

“fun multi() = num1.toFloat() * num2.toFloat()”.

If I change to number works here.

ex:

“fun multi() = 2 * 4” works here.

The answer can be on Jetpack Compose too.