I am new to flutter. Stuck in below issue.

```
  double weight = 0;

  weightIncrement() {
    setState(() {
      weight += 1;
    });
  }

  weightDecrement() {
    setState(() {
      weight -= 1;
    });
  }
      Text(
        cardType == CardType.age ? "$age".toString() : "$weight".toString())

```

Using above on some button. And setting value to Text throws below error.
I/flutter (22691): The following assertion was thrown building Calculator(dirty, state: \_CalculatorState#82a4b):
I/flutter (22691): type 'int' is not a subtype of type 'double' of 'function result'