Issue on Deselecting All Checkbox on Un checking one of Child

I am trying to use jquery to check all checkboxes using below code which working fine on toggling select all on check and un check the slectAll

Now I want to uncheck the slectAll in case of a situation if a user un-check one of the ieldset checkboxes. I tried this code

    $.each($("input[name='numbers']:not(:checked)"), function () {
        $('input:checkbox[name=slectAll]').prop("checked", false);
    });

but it didn't do the job!

<input id="boxid" type="checkbox" name="slectAll">
<label for="boxid">Select All</label>
<fieldset id="group_1">
    <input type="checkbox" name="numbers[]" value="0" />
    <input type="checkbox" name="numbers[]" value="1" />
    <input type="checkbox" name="numbers[]" value="2" />
    <input type="checkbox" name="numbers[]" value="3" />
    <input type="checkbox" name="numbers[]" value="4" />
</fieldset>

and the jquery file is

$(function () {
    $('input:checkbox[name=slectAll]').change(function () {
        if ($(this).is(':checked')) {
            $('#group_1').find(':checkbox').prop("checked", true);
        } else {
            $('#group_1').find(':checkbox').prop("checked", false);
        }
    });

    $.each($("input[name='numbers']:not(:checked)"), function () {
        $('input:checkbox[name=slectAll]').prop("checked", false);
    });

});

can you please let me know how to fix this? thanks