home_page.dart

...

Consumer<ValueBloc>(
  builder: (BuildContext context, ValueBloc valueBloc) {
    return Text("Value: ${valueBloc.value.toStringAsPrecision(1)}",
      style: TextStyle(
        color: Colors.white,
        fontSize: 24,
        fontWeight: FontWeight.bold,
      ),
    );
  },
),

...

Consumer<ValueBloc>(
  builder: (BuildContext context, ValueBloc valueBloc) {
    return Slider(
    activeColor: Colors.white,
    inactiveColor: Colors.white,
    min: 0.0,
    max: 1.0,
    onChanged: valueBloc.onChangeValue,
    value: valueBloc.value);
  },
),