app-add-numbers.component.ts

import { Component } from "@angular/core";

@Component({
  selector: "app-add-numbers",
  template: `
    <input type="number" [(ngModel)]="num1" /> +
    <input type="number" [(ngModel)]="num2" />&nbsp;
    <button (click)="add()">Add</button>&nbsp;
    <label>{{ result }}</label>
  `,
})
export class AppAddNumbersComponent {
  num1 = 0;
  num2 = 0;
  result = 0;
  add() {
    this.result = this.sum(this.num1, this.num2);
  }
  sum(a: number, b: number) {
    return a + b;
  }
}