Bidirectional Property Bindings
Property Bindings have the ability to become Bidirectional, meaning instead of having the binding go one way only, it will work both ways, even with just the one binding. Take the previous example with the Numeric Text Field and Slider again. When changing the value of the Slider, the Numeric Text Field would update, but updating the value of the Numeric Text Field would not update the Slider. If we reopen the binding on the Value (Integer) property of the Numeric Text Field, we can see in the bottom left corner a checkbox for Bidirectional.

Check the Bidirectional option and then save the binding. It will now be a bidirectional binding.