연산이랑 onkeyup 질문입니다. 도와주ㅡ세요~ 채택완료

<td>

<?php
$a0 = $wr_data['apiece']; //할인금액
$b0 = $wr_data['normal_price']; //소계
$wr_data['apiece'] = number_format(intval($b0/$a0 * 100));


?>


<script>
    function printdiscount() { // input -> 값 전달하기
        const discount = document.getElementById('discount').value;
        document.getElementById("apiece").innerText = discount;
    }
</script>


                                            
<!-- <input type="text" class="form-control input-sm text-center" name="wr_data[apiece]" value="<?php echo $wr_data['apiece']; //단가 ?>"  /> -->
<input type="text" id='discount' onchange='printdiscount()' name="wr_data[apiece]" class="form-control input-sm" value="<?php echo $wr_data['apiece'];?>" onkeyup="document.getElementById('cal_discount').innerText=(parseInt(this.value)|-0);" />                                            
                                                    
</td>


<td><!-- //////////////////////할인////////////////////////// -->
<input type="hidden" id='discount' onchange='printdiscount()' name="wr_data[discount]" value="<?php echo $wr_data['discount']; ?>" />
<?php if ($w == '')  { ?><span id='cal_discount'></span><span> %</span><?php } ?>
<?php if ($w == 'u') { ?><span id='cal_discount' value="<?php echo $wr_data['discount'];?>" class="text-danger"><?php echo $wr_data['discount'];?> </span><span> %</span><?php } ?> 

<?php
    list($licence_text, $licence_price) = explode("/", $wr_data['discount']);
    echo $licence_price;
?>

</td>