jquery를 이용한 특정영역에 input Max값 Min값 구하기

<script type="text/javascript">
$(document).ready(function() {
	//임의 숫자 세팅
	$("input[name='ipt_calc']").each(function(){
		$(this).val((Math.random() * 100).toFixed());
	});
});

function fnCalc(targetNm){
	//최대값 구하기
	let maxValue = Math.max.apply(null, $("#" + targetNm + "Area input[type='number']").map(function (){return $(this).val();}).get());
	//0을 제외한 최소값 구하기
	let minValue = Math.min.apply(null, $("#" + targetNm + "Area input[type='number']").map(function (){return $(this).val() == 0 ? 99999 : $(this).val();}).get());

	$("#sp_area").text(targetNm);
	$("#sp_max").text(maxValue);
	$("#sp_min").text(minValue);
}
</script>

	<div>
		<div>area : <span id="sp_area"></span></div>
		<div>max : <span id="sp_max"></span></div>
		<div>min : <span id="sp_min"></span></div>
	</div>
	<br /><br />
	<div id="firstArea">
		<div>firstArea <button type="button" onclick="fnCalc('first');">calc</button></div>
		<div><input type="number" name="ipt_calc" value="" /></div>
		<div><input type="number" name="ipt_calc" value="" /></div>
		<div><input type="number" name="ipt_calc" value="" /></div>
		<div><input type="number" name="ipt_calc" value="" /></div>
		<div><input type="number" name="ipt_calc" value="" /></div>
		<div><input type="number" name="ipt_calc" value="" /></div>
	</div>
	<div id="secondArea">
		<div>secondArea <button type="button" onclick="fnCalc('second');">calc</button></div>
		<div><input type="number" name="ipt_calc" value="" /></div>
		<div><input type="number" name="ipt_calc" value="" /></div>
		<div><input type="number" name="ipt_calc" value="" /></div>
		<div><input type="number" name="ipt_calc" value="" /></div>
		<div><input type="number" name="ipt_calc" value="" /></div>
		<div><input type="number" name="ipt_calc" value="" /></div>
	</div>