title: how do you validate sub digit values with numbers allowing .5 or .0 without an input mask?
body: <p>My clients are getting frustrated at typing in 000.5 or 001.0 in a number of days field due to being forced to use an input mask to prevent invalid values.   </p>
  
  <p>I have managed to sort out validation for a range of numerical values 180.0 - 0.5 allowing only half or whole values to be entered.  An example of values not allowed:-</p>
  
  <pre><code>1.2
  1.02
  1.222  
  0.01
  0.001
  181.0   &lt;-- above the range
  </code></pre>
  
  <p>The only values allowed are:-</p>
  
  <pre><code>0.5  - 180.0
  </code></pre>
  
  <p>but this is only possible with an input mask.  Using the formulae :-</p>
  
  <pre><code> (([NoOfDays]*10) Mod 5)=0 And &lt;=180 And &gt;=0.5
  </code></pre>
  
  <p>and an input mask of 000.0 or 009.0  you can prevent sub decimal values but without it, it appears to be not possible with this formulae.</p>
  
  <p>Without the input mask customers can enter:- 1.05, 2.51   etc.</p>
  
  <p>Is there a formulae for solving this?</p>