Getting values from checkbox, add them, and display the result
<div id="pakker">
<input type="checkbox" value="39" />test 1<br/>
<input type="checkbox" value="79" />test 2<br/>
<input type="checkbox" value="29" />test 3<br/>
<input type="checkbox" value="49" />test 4<br/>
ect
</div>

var total = 0;
$("#pakker input[type='checkbox']:checked").each(function() {
    total += parseInt(this.value, 10);
});
//Do whatever you like with total

var result = 0;
$("#pakker input:checked").each(function(){ result += $(this).val(); });

alert(result );

var sum = $('#pakker :checkbox:checked').map(function() {
   return parseInt(this.value, 10);
}).get().reduce(function(prev, current) {
    return prev + current;
}, 0);

$(document).ready(function(){
        $("input[type='checkbox']").click(function(){
            var total = 0;
            $("#pakker input[type='checkbox']:checked").each(function() {
                total += parseInt(this.value, 10);
            });
            $('#result').html(total);
        });
    });

<span id="result"></span>
<div id="pakker">
<input type="checkbox" value="39" />test 1 - value 39<br/>
<input type="checkbox" value="79" />test 2 - value 79<br/>
<input type="checkbox" value="29" />test 3 - value 29<br/>
<input type="checkbox" value="49" />test 4 - value 49<br/>
ect
</div>