diff --git a/CalculatorMVVM/ViewModels/MainWindowViewModel.cs b/CalculatorMVVM/ViewModels/MainWindowViewModel.cs
index b04eccc..e00e975 100644
--- a/CalculatorMVVM/ViewModels/MainWindowViewModel.cs
+++ b/CalculatorMVVM/ViewModels/MainWindowViewModel.cs
@@ -10,9 +10,13 @@ public class MainWindowViewModel : BindableBase
         public string Num1
         {
             get => _Num1;
-            set {
+            set
+            {
                 SetProperty(ref _Num1, value);
                 AddCommand.RaiseCanExecuteChanged();
+                SubCommand.RaiseCanExecuteChanged();
+                MultiCommand.RaiseCanExecuteChanged();
+                DivideCommand.RaiseCanExecuteChanged();
             }
         }
 
@@ -25,6 +29,9 @@ public string Num2
             {
                 SetProperty(ref _Num2, value);
                 AddCommand.RaiseCanExecuteChanged();
+                SubCommand.RaiseCanExecuteChanged();
+                MultiCommand.RaiseCanExecuteChanged();
+                DivideCommand.RaiseCanExecuteChanged();
             }
         }
 
@@ -33,7 +40,7 @@ public string Result
         {
             get => _Result;
             set => SetProperty(ref _Result, value);
-            
+
         }
 
         public DelegateCommand AddCommand { get; }
@@ -44,6 +51,12 @@ public string Result
         public MainWindowViewModel()
         {
             AddCommand = new DelegateCommand(Add, CanCalculate);
+
+            SubCommand = new DelegateCommand(Sub, CanCalculate);
+
+            MultiCommand = new DelegateCommand(Multi, CanCalculate);
+
+            DivideCommand = new DelegateCommand(Divide, CanDivide);
         }
 
         private void Add()
@@ -53,14 +66,17 @@ private void Add()
 
         private void Sub()
         {
+            Result = (_dblNum1 - _dblNum2).ToString();
         }
 
         private void Multi()
         {
+            Result = (_dblNum1 * _dblNum2).ToString();
         }
 
         private void Divide()
         {
+            Result = (_dblNum1 / _dblNum2).ToString();
         }
 
         public bool CanCalculate()
@@ -77,7 +93,20 @@ public bool CanCalculate()
 
         public bool CanDivide()
         {
-            return default;
+            var problem = !double.TryParse(Num1, out _dblNum1) || !double.TryParse(Num2, out _dblNum2);
+
+            if (problem)
+            {
+                return false;
+            }
+            else if(_dblNum2 == 0)
+            {
+                return false;
+            }
+            else
+            {
+                return true;
+            }
         }
     }
 }
diff --git a/CalculatorMVVM/Views/MainWindow.xaml b/CalculatorMVVM/Views/MainWindow.xaml
index 866aecb..cd91d5b 100644
--- a/CalculatorMVVM/Views/MainWindow.xaml
+++ b/CalculatorMVVM/Views/MainWindow.xaml
@@ -20,9 +20,12 @@
         <TextBox x:Name="txtNum2" Margin="5" Grid.Row="0" Grid.Column="2" Grid.ColumnSpan="2" Text="{Binding Num2, UpdateSourceTrigger=PropertyChanged}" />
 
         <Button x:Name="btnAdd" Margin="5" Grid.Row="1" Command="{Binding AddCommand}" Grid.Column="0" Content="+"/>
-
+        <Button x:Name="btnSub" Margin="6,5.333,4.667,5.333" Grid.Row="1" Command="{Binding SubCommand}" Grid.Column="1" Content="-"/>
+        <Button x:Name="btnDivide" Margin="5.333,6.333,4.667,4.667" Grid.Row="1" Command="{Binding DivideCommand}" Grid.Column="3" Content="/"/>
+        <Button x:Name="btnMulti" Margin="5.333,5.333,4.667,6" Grid.Row="1" Command="{Binding MultiCommand}" Grid.Column="2" Content="*"/>
 
         <TextBox x:Name="txtResult" Margin="5" Grid.Row="2" Grid.Column="0" Grid.ColumnSpan="4" Text="{Binding Result}"/>
 
+
     </Grid>
 </Window>