<ViewBox>
    <YourControl />
</ViewBox>

<Viewbox Width="80" Margin="12">
        <RelativePanel Width="200" Height="140" Background="DarkBlue" Padding="12">

            <TextBlock x:Name="number"
                       Text="XXXX XXXX XXXX XXXX"
                       Foreground="White"
                       RelativePanel.AlignVerticalCenterWithPanel="True"
                       RelativePanel.AlignHorizontalCenterWithPanel="true"/>

            <TextBlock x:Name="name"
                       Text="FIRST NAME"
                       Foreground="White"
                       RelativePanel.AlignLeftWith="number"
                       RelativePanel.Below="number"
                       Margin="0,12,0,0"/>

            <TextBlock x:Name="date"
                       Text="MM/YY"
                       Foreground="White"
                       RelativePanel.AlignRightWith="number"
                       RelativePanel.Below="number"
                       Margin="0,12,0,0"/>
        </RelativePanel>
    </Viewbox>

    <Viewbox Width="160" Margin="12">
        <RelativePanel Width="200" Height="140" Background="DarkBlue" Padding="12">

            <TextBlock x:Name="number1"
                       Text="XXXX XXXX XXXX XXXX"
                       Foreground="White"
                       RelativePanel.AlignVerticalCenterWithPanel="True"
                       RelativePanel.AlignHorizontalCenterWithPanel="true"/>

            <TextBlock x:Name="name1"
                       Text="FIRST NAME"
                       Foreground="White"
                       RelativePanel.AlignLeftWith="number1"
                       RelativePanel.Below="number1"
                       Margin="0,12,0,0"/>

            <TextBlock x:Name="date1"
                       Text="MM/YY"
                       Foreground="White"
                       RelativePanel.AlignRightWith="number1"
                       RelativePanel.Below="number1"
                       Margin="0,12,0,0"/>
        </RelativePanel>
    </Viewbox>

    <Viewbox Width="320" Margin="12">
        <RelativePanel Width="200" Height="140" Background="DarkBlue" Padding="12">

            <TextBlock x:Name="number2"
                       Text="XXXX XXXX XXXX XXXX"
                       Foreground="White"
                       RelativePanel.AlignVerticalCenterWithPanel="True"
                       RelativePanel.AlignHorizontalCenterWithPanel="true"/>

            <TextBlock x:Name="name2"
                       Text="FIRST NAME"
                       Foreground="White"
                       RelativePanel.AlignLeftWith="number2"
                       RelativePanel.Below="number2"
                       Margin="0,12,0,0"/>

            <TextBlock x:Name="date2"
                       Text="MM/YY"
                       Foreground="White"
                       RelativePanel.AlignRightWith="number2"
                       RelativePanel.Below="number2"
                       Margin="0,12,0,0"/>
        </RelativePanel>
    </Viewbox>
</StackPanel>