How to save a piece of XAML markup as a template?

Question

.NET

Hello

When building a certain application on WPF, and more specifically, a calculator (Similar to the Miscrosoft calculator), a question arose, the essence of which is that I do not know how to make dynamic markup in XAML.
The point is that, according to the idea, when I click on the type of calculator in the sidebar, I need to display a completely different markup for another calculator (For example, for engineering) on ​​the same window and call it every time I click the button, and the previous markup is simply delete.

Purely logically, it’s really possible to do this, but I don’t know how