<!DOCTYPE html>
<html>
<head>
<title>Simple Math Task</title>
<!-- stylesheets -->
<link rel="stylesheet" type="text/css" href="../core/core.css">
<!-- JS -->
<script src="../core/core.js"></script>
<script src="../core/d3.v3.min.js"></script>
<script src="../common/ui_utils.js"></script>

<style>
#area { text-align: center; }
#math-problem { height: 30px; font-size: 30px; display: inline-block; }
#area #math-answer { display: inline-block; height: 30px; width: 25%; margin-left: 4px;
  vertical-align: top; 