textProperty valueProperty.
, .
Itachi valueProperty() ChangeListener .

import javafx.application.Application;
import javafx.beans.binding.Bindings;
import javafx.scene.Scene;
import javafx.scene.control.*;
import javafx.scene.layout.VBox;
import javafx.stage.Stage;
public class Slide extends Application {
@Override public void start(Stage stage) {
Label label = new Label();
Slider slider = new Slider(1, 11, 5);
label.textProperty().bind(
Bindings.format(
"%.2f",
slider.valueProperty()
)
);
VBox layout = new VBox(10, label, slider);
layout.setStyle("-fx-padding: 10px; -fx-alignment: baseline-right");
stage.setScene(new Scene(layout));
stage.setTitle("Goes to");
stage.show();
}
public static void main(String[] args) { launch(args); }
}