How to output text from a button in AngularJS when it is clicked?

Question

Angular

I started learning Angular, I wanted to make a calculator on it. How to make it so that when you click on a button with a number in the input text, the value of this button is displayed and the number is typed until you press +, -, etc.? The number buttons themselves are created like this:

<md-button ng-repeat="x in [1,2,3,4,5,6,7,8,9,0]" class="md-fab" href="" ng-disabled="false" aria-label="description" md-no-ink="true" ng-click="" md-ripple-size="full">{{x}}</md-button>

Don't kick too hard, I only took up Angular yesterday. I understand that this is easy to implement on jQuery, but Angular is needed.
PS Tell me, what literature or video courses on the subject are really worth studying, there are a lot of them on the Web, I really don’t want to spend time on some bullshit.