Here the original source code for this module

<div class="row">
    <div class="col-sm-3">

        <div class="counter style-2">

            <span class="timer counter-value" data-from="1" data-to="457" data-speed="10000"></span>
            <div class="counter-details">Cups of coffe</div>

        </div>

    </div>
    <div class="col-sm-3">

        <div class="counter style-2">

            <span class="timer counter-value" data-from="1" data-to="169" data-speed="10000"></span>
            <div class="counter-details">Smart Clients</div>

        </div>

    </div>
    <div class="col-sm-3">

        <div class="counter style-2">

            <span class="timer counter-value" data-from="1" data-to="372" data-speed="10000"></span>
            <div class="counter-details">Great ideeas</div>

        </div>
    </div>
    <div class="col-sm-3">

        <div class="counter style-2">

            <span class="timer counter-value" data-from="1" data-to="206" data-speed="10000"></span>
            <div class="counter-details">Projects</div>

        </div>
    </div>
</div>

Like I said before, you need to switch the joomla editor to codemirror or none before editing. Tinymce or Jce editor will remove the span tags or i tags automatically.