app idea

<style>
.l1{
background-color:blue;
}
.l2{
background-color:55ff00;
}
.l3{
background-color:yellow;
}
.l4{
background-color:orange;
}
</style>
<table class="l1"><tr><td><table class="l2"><tr><td><table class="l3"><tr><td>5</td><td>x</td></tr></table></td><td> +</td><td> <table class="l3"><tr><td>4</td></tr></table></td></tr></table></td><td>=</td><td><table class="l2"><tr><td>9</td></tr></table></td></tr></table>
<h2>Functions</h2>
<table id="functions" border="1"><tr><td><b>Raise to a power</b></td><td><b>Take a power of x</b></td></tr>
<tr><td><input type="text" /></td><td><input type="text" />x^<input type="number" /></td></tr>
<tr><td></table>