Math functions in angular2 bindings

You can try this :

@Component({
  selector: 'my-app',
  template: `
    <div>
      <h2>Hello {{math.round(number)}}</h2>
    </div>
  `,
})
export class App {
  number = 2.5;
  math = Math;
}

DEMO

For rounding numbers in Angular templates, you can use the DecimalPipe: {{ value | number }}

See all the rounding options in https://angular.io/api/common/DecimalPipe

For all the built-in pipes, check https://angular.io/api?type=pipe