Calculator Picker
The RadCalculatorPicker control is a drop down button with a RadCalculator in its drop down content. The button content shows the calculated value of the calculator.
Defining RadCalculatorPicker
<telerikControls:RadCalculatorPicker Height="30" Width="200" />
telerikControls namespace points to xmlns:telerikControls="using:Telerik.UI.Xaml.Controls".
RadCalculatorPicker example
The drop down state can be controlled manually with the IsDropDownOpen property of RadCalculatorPicker.
Opening the drop down content in code
this.calculatorPicker.IsDropDownOpen = true;