Try to clarify your question, i've a hard time understanding what you want. Does my-text-field and my-number-field value has to be based on the checked input value ?
Ok, this should work.
$("#beastmode").click(function () {
if ($(this).prop('checked') === true) {
$('#mytextfield').show();
$('#mynumberfield').show();
$('input[name="mytextfield"]').prop('required',true);
$('input[name="mynumberfield"]').prop('required',true);
} else {
$('#mytextfield').hide();
$('#mynumberfield').hide();
$('input[name="mytextfield"]').prop('required',false);
$('input[name="mynumberfield"]').prop('required',false);
}
});
and the fiddle http://jsfiddle.net/n67Mf/1/
I just closed some tag and remove some unnecessary code.