# Structure

This article describes the inner structure and organization of the elements which build the **RadCalculatorDropDown** control.

**RadCalculatorDropDown** consists of two parts - editable part which is the actual editor and a popup hosting the calculator.

> caption Figure 1: RadCalculatorDropDown\`s Element Hierarchy

![WinForms RadCalculatorDropDown Element Hierarchy](https://www.telerik.com/products/winforms/documentation/assets/ae3bfec1d0163299a0ca7d71f51fcc47/editors-calculator-element-structure001.png)

> caption Figure 2: RadCalculatorDropDown Structure

![WinForms RadCalculatorDropDown Structure](https://www.telerik.com/products/winforms/documentation/assets/aae3cf7573afda66423c4bb9a51a0a63/editors-calculator-element-structure002.png)

## Editable Area

The editable area consists of three elements:

* **Editable Area**: Contains the editor repsponsible for handling user input.

  * **RadCalculatorMemoryElement**: This element gets visible when the memory functions of the calculator are used.

  * **RadCalculatorEditorContentElement**: This is the editable area of the control.

  * **RadCalculatorArrowButtonElement**: This the arrow button which opens the popup of the control.

## Drop-down Part

The popup part consists of six elements:

* **Drop-Down**: Handles the arithmetic operations.

  * **RadCalculatorMemoryButtonElement**: This is the type of the buttons for memory operations

  * **RadCalculatorOperationButtonElement**: This type is used by the buttons resposinble for different calculation operations (subscription, addition, etc).

  * **RadCalculatorEqualsButtonElement**: This class is used by the equals button.

  * **RadCalculatorCommandButtonElement**: This class is used by the command buttons (CE, C).

  * **RadCalculatorDeleteButtonElement**: This type is used by the delete button.

  * **RadCalculatorDigitButtonElement**: This type is used by the digit buttons.

## See Also

* [Design Time](https://www.telerik.com/products/winforms/documentation/controls/editors/calculatordropdown/design-time/smart-tag)
* [Getting Started](https://www.telerik.com/products/winforms/documentation/controls/editors/calculatordropdown/getting-started)