<ul >
<li class="round">
    <a href="#"></a>

        <ul class="text">
            <li class="text"><a href="#" class="number">15</a></li>
        </ul>

</li>
</ul>


.round {
display: block;
position: relative;

left: 0;
right: 0;
top: 0;
bottom: 0;
margin-left: auto;
margin-right: auto;

width: 100px;
height: 100px;
border-radius: 50%;
background-color: #000;
}

.text {
display: block;
position: relative;

bottom: 0;
left: 0;
right: 0;
top: 0;
margin-left: auto;
margin-right: auto;

}

.number
{
display: block;
position: relative;

bottom: 0;
left: 0;
right: 0;
top: 0;
margin-left: auto;
margin-right: auto;
}