JSFiddle - React, Tailwind, and code Playground

HTML

<script src="http://www.pengoworks.com/workshop/jquery/calculation/jquery.calculation.js"></script>
<label>Quantity</label>
<input type="text" ID="qty_item_1" runat="server" MaxLength="3" value="0" />

<ul>                
                <li class="one"><span id="quant_1"></span></li>
                <li class="two">Product 1</li>
                <li class="three"><span id="price_item_1">£1.00</span></li>
                <li class="four"><span id="total_item_1">£0.00</span></li>
            </ul>


   
<label>Quantity</label>
<input type="text" ID="qty_item_2" runat="server" MaxLength="3" value="0" /> 


<ul>   
                <li class="one"><span id="quant_2"></span></li>
                <li class="two">Product 2</li>
                <li class="three"><span id="price_item_2">£13.00</span></li>
                <li class="four"><span id="total_item_2">£0.00</span></li>
            </ul>

CSS

label {
    width:250px;
height:25px;    
}

ul {
    width:250px;
    height:50px;
}

li {
float:left;  
margin:0 10px;    
}

JavaScript

$(document).ready(
        function (){
            // update the plug-in version
            $("#idPluginVersion").text($.Calculation.version);
                        
            // bind the recalc function to the quantity fields
            $("input[id^=qty_item_]").bind("keyup", recalc);
            // run the calculation function now
            
            recalc();

        }
    );
    
    function recalc(){
        
        $("[id^=quant_]").text($("input[id^=qty_item_]").val());
        
        $("[id^=total_item]").calc(
            // the equation to use for the calculation
            "qty * price",
            // define the variables used in the equation, these can be a jQuery object
            {
                qty: $("input[id^=qty_item_]"),
                price: $("[id^=price_item_]")
                
                //if ($("[id^=total_item]").val().length > 0.00){
                    //$("[id^=total_item]").addClass('enquire');
                //}
                
            },
            // define the formatting callback, the results of the calculation are passed to this function
            function (s){
                // return the number as a dollar amount
                return "£" + s.toFixed(2);
            },
            // define the finish callback, this runs after the calculation has been complete
            function ($this){
                // sum the total of the $("[id^=total_item]") selector
                var sum = $this.sum();
                                
                $("#ctl00_EnquiryForm1_grandTotal").val(
                    // round the results to 2 digits
                    "£" + sum.toFixed(2)
                );
            }
        );
    }