TipCalcPage.xaml

<?xml version="1.0" encoding="utf-8" ?>
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
             xmlns:tipCalc="clr-namespace:TipCalc;assembly=TipCalc"
             x:Class="TipCalc.TipCalcPage">
    <ContentPage.Padding>
        <OnPlatform x:TypeArguments="Thickness">
            <On Platform="iOS">10, 80, 10, 0</On>
            <On Platform="Android">5, 0, 5, 0</On>
            <On Platform="UWP">5, 0, 5, 0</On>
        </OnPlatform>
    </ContentPage.Padding>
    <ContentPage.Resources>
        <ResourceDictionary>
            <tipCalc:TipCalcModel x:Key="model" TipPercent="15" />
            <tipCalc:DoubleToStringConverter x:Key="stringConverter" />
            <tipCalc:DoubleRoundingConverter x:Key="roundConverter" />
        </ResourceDictionary>
    </ContentPage.Resources>
    <Grid BindingContext="{StaticResource model}">
        <Grid.RowDefinitions>
            <RowDefinition Height="Auto" />
            <RowDefinition Height="Auto" />
            <RowDefinition Height="Auto" />
            <RowDefinition Height="Auto" />
            <RowDefinition Height="Auto" />
            <RowDefinition Height="Auto" />
        </Grid.RowDefinitions>
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="*" />
            <ColumnDefinition Width="*" />
        </Grid.ColumnDefinitions>
        <!-- Row 0 -->
        <Label Text="Food &amp; Drink:" Grid.Row="0" Grid.Column="0"  HorizontalTextAlignment="End" VerticalTextAlignment="Center" />
        <Entry Grid.Row="0" Grid.Column="1" Keyboard="Numeric" Placeholder="Subtotal" Text="{Binding SubTotal, Converter={StaticResource stringConverter}}" />
        <!-- Row 1 -->
        <Label Text="Total after Tax:" Grid.Row="1" Grid.Column="0"  HorizontalTextAlignment="End" VerticalTextAlignment="Center" />
        <Entry Grid.Row="1" Grid.Column="1" Keyboard="Numeric" Placeholder="Receipt total" Text="{Binding PostTaxTotal, Converter={StaticResource stringConverter}}" />
        <!-- Row 2 -->
        <Label Text="Tip Percent:" Grid.Row="2" Grid.Column="0"  HorizontalTextAlignment="End" VerticalTextAlignment="Center" />
        <Entry Grid.Row="2" Grid.Column="1" Keyboard="Numeric" Text="{Binding TipPercent, Converter={StaticResource stringConverter}}" />
        <!-- Row 3 -->
        <Slider Grid.Row="3" Grid.Column="0" Grid.ColumnSpan="2" Minimum="0" Maximum="100" Value="{Binding TipPercent, Mode=TwoWay, Converter={StaticResource roundConverter}, ConverterParameter=0.5}" />
        <!-- Row 4 -->
        <Label Text="Tip Amount:" Grid.Row="4" Grid.Column="0"  HorizontalTextAlignment="End" VerticalTextAlignment="Center" />
        <ContentView BackgroundColor="#40808080" Grid.Row="4" Grid.Column="1" Padding="10, 10, 40, 10">
            <Label Text="{Binding TipAmount, StringFormat='{0:C}'}"  HorizontalTextAlignment="End" />
        </ContentView>
        <!-- Row 5 -->
        <Label Text="Total:" Grid.Row="5" Grid.Column="0"  HorizontalTextAlignment="End" VerticalTextAlignment="Center" />
        <ContentView BackgroundColor="#40808080" Grid.Row="5" Grid.Column="1" Padding="10, 10, 40, 10">
            <Label Text="{Binding Total, StringFormat='{0:C}'}"  HorizontalTextAlignment="End" />
        </ContentView>
    </Grid>
</ContentPage>