dmitry111,
<html>
<head>
<meta charset="UTF-8">
<title>выпвып</title>
<script>
window.onload = function () {
document.getElementById("inp").onclick = function (e) {
e = e || event;
var target = e.target || e.srcElement;
if (target.tagName == "INPUT" && target.type == "checkbox") {
document.getElementById("sum").innerHTML = target.value;
}
}
}
</script>
</head>
<body>
<span id="inp">
<input type="checkbox" value="2">
<input type="checkbox" value="4">
<input type="checkbox" value="234">
<input type="checkbox" value="243">
<input type="checkbox" value="25432">
</span>
<div id="box">Сумма значений: <span id="sum"></span></div>
</body>
</html>