title: Vuetify v-text-field change value
body: <p>how can i manipulate input value.
  Show hier is example</p>
  
  <pre><code>`https://jsfiddle.net/mbqjp4ax/`
  </code></pre>
  
  <p>if number greater than 5, number 9 should be entered.
  if I enter more than 5 it works fine but if I keep typing it will not work as expected. </p>