MainWindow.xaml

<Window x:Class="Calculator.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:Calculator"
        mc:Ignorable="d"
        Title="MainWindow" Height="525" Width="350">
    <Grid Margin="10">
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="*"/>
            <ColumnDefinition Width="*"/>
            <ColumnDefinition Width="*"/>
            <ColumnDefinition Width="*"/>
        </Grid.ColumnDefinitions>
        <Grid.RowDefinitions>
            <RowDefinition Height="2*"/>
            <RowDefinition Height="*"/>
            <RowDefinition Height="*"/>
            <RowDefinition Height="*"/>
            <RowDefinition Height="*"/>
            <RowDefinition Height="*"/>
        </Grid.RowDefinitions>
        <!--Below code sets the calculate results visual.-->
        <Label x:Name="ResultLabel"
               Content="0"
               HorizontalAlignment="Right"
               VerticalAlignment="Bottom"
               FontSize="60"
               Grid.ColumnSpan="4"/>
        <!--Below code is for the Buttons of the Calculator.-->
        <Button x:Name="AcBtn"
                Content="A/C"
                Margin="5"
                Grid.Row="1"/>
        <Button x:Name="NegativeBtn"
                Content="+/-"
                Margin="5"
                Grid.Row="1"
                Grid.Column="1"/>
        <Button x:Name="PercentageBtn"
                Content="%"
                Margin="5"
                Grid.Row="1"
                Grid.Column="2"/>
        <Button x:Name="DivideBtn"
                Click="OperationBtn_Click"
                Content="/"
                Margin="5"
                Grid.Row="1"
                Grid.Column="3"/>

        <Button x:Name="SevenBtn"
                Click="NumberBtn_Click"
                Content="7"
                Margin="5"
                Grid.Row="2"/>
        <Button x:Name="EightBtn"
                Click="NumberBtn_Click"
                Content="8"
                Margin="5"
                Grid.Row="2"
                Grid.Column="1"/>
        <Button x:Name="NineBtn"
                Click="NumberBtn_Click"
                Content="9"
                Margin="5"
                Grid.Row="2"
                Grid.Column="2"/>
        <Button x:Name="TimesBtn"
                Click="OperationBtn_Click"
                Content="*"
                Margin="5"
                Grid.Row="2"
                Grid.Column="3"/>

        <Button x:Name="FourBtn"
                Click="NumberBtn_Click"
                Content="4"
                Margin="5"
                Grid.Row="3"/>
        <Button x:Name="FiveBtn"
                Click="NumberBtn_Click"
                Content="5"
                Margin="5"
                Grid.Row="3"
                Grid.Column="1"/>
        <Button x:Name="SixBtn"
                Click="NumberBtn_Click"
                Content="6"
                Margin="5"
                Grid.Row="3"
                Grid.Column="2"/>
        <Button x:Name="MinusBtn"
                Click="OperationBtn_Click"
                Content="-"
                Margin="5"
                Grid.Row="3"
                Grid.Column="3"/>
        <Button x:Name="OneBtn"
                Click="NumberBtn_Click"
                Content="1"
                Margin="5"
                Grid.Row="4"/>
        <Button x:Name="TwoBtn"
                Click="NumberBtn_Click"
                Content="2"
                Margin="5"
                Grid.Row="4"
                Grid.Column="1"/>
        <Button x:Name="ThreeBtn"
                Click="NumberBtn_Click"
                Content="3"
                Margin="5"
                Grid.Row="4"
                Grid.Column="2"/>
        <Button x:Name="PlusBtn"
                Click="OperationBtn_Click"
                Content="+"
                Margin="5"
                Grid.Row="4"
                Grid.Column="3"/>

        <Button x:Name="ZeroBtn"
                Click="NumberBtn_Click"
                Content="0"
                Margin="5"
                Grid.ColumnSpan="2"
                Grid.Row="5"/>
        <Button x:Name="PointBtn"
                Click="PointBtn_Click"
                Content="."
                Margin="5"
                Grid.Row="5"
                Grid.Column="2"/>
        <Button x:Name="EqualsBtn"
                Content="="
                Margin="5"
                Grid.Row="5"
                Grid.Column="3"/>
    </Grid>
</Window>