Binding in XAML

Question

I have created three sliders to quickly input data into Windows Store APP. Range of each slider is 0-9, all together represents a value from range 000 - 999 in TextBox.

I can calculate the value using following Formula

int result = Slider1.Value * 100 + Slider2.Value * 10 + Slider3.Value;

I can simply attach this to every slider's ValueChanged Event, but there is a more elegant way Via XAML Binding. I created something like this

public class MyViewModel
{
    public MyViewModel() { }

    public double TotalValue { get; set; }
}

but I cannot access any of sliders. Is there any way to pass them as constructor parameters? Or any other way to perform this binding?

EDIT Adding data context

<Page.DataContext>
    <local:MyViewModel/>
</Page.DataContext>

Answer 1

Bind every slider value to a property in the viewmodel:

(make sure to implement INotifyPropertyChanged)

public class MyViewModel:INotifyPropertyChanged
    {
        public MyViewModel()
        {

        }

        private double valueSlider1;
        public double ValueSlider1
        {
           get { return valueSlider1; }
           set
           {
              valueSlider1 = value;
              RaisePropertyChanged("ValueSlider1");
              RaisePropertyChanged("TotalValue ");
           }
        }
        private double valueSlider2;
        public double ValueSlider2
        {
           get { return valueSlider2; }
           set
           {
              valueSlider2 = value;
              RaisePropertyChanged("ValueSlider2");
              RaisePropertyChanged("TotalValue ");
           }
        }
        private double valueSlider3;
        public double ValueSlider3
        {
           get { return valueSlider3; }
           set
           {
              valueSlider3 = value;
              RaisePropertyChanged("ValueSlider3");
              RaisePropertyChanged("TotalValue ");
           }
        }
        public double TotalValue
        {
           get { return ValueSlider1*100+ValueSlider2*10+ValueSlider3; }
        }

        public event PropertyChangedEventHandler PropertyChanged;
        private void RaisePropertyChanged(string propertyName)
        {
             var handler = this.PropertyChanged;
             if (handler != null)
             {
                handler(this, new PropertyChangedEventArgs(propertyName));
             }
        }
    }

Then, apply the binding to the sliders in this way:

<Slider Value="{Binding SliderValue1, Mode=TwoWay}" />