SOURCE

var app = new Vue({
  el: '#app',
  data: function() {
    return {
      // count: 100
    }
  },
  components: ['counts']
});

Vue.component('counts', {
  template: '<h2>{{counts.count}}</h2>',
  data: function (){
    return {
      count: 100
    }
  },
  methods: {
    minus: function() {
      this.count -= 1;
    }
  },
  mounted() {
    var Timer = null;
    Timer = setInterval(function() {
      this.minus()
      if (this.count <= 0) {
        clearInterval(Timer);
      }
    }, 50);
  }
});

<div id="app">
  <counts></counts>
</div>