index.html

<!DOCTYPE html>
<html lang="pt-br">

<head>
    <link rel="stylesheet" href="https://use.fontawesome.com/releases/v5.8.1/css/all.css"
        integrity="sha384-50oBUHEmvpQ+1lW4y57PTFmhCaXp0ML5d60M1M7uH2+nqUivzIebhndOJK28anvf" crossorigin="anonymous">
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <link rel="stylesheet" href="assets/css/style.css">
    <link rel="stylesheet" href="assets/css/animate.css">

    <title>Calculadora</title>
</head>

<body>

    <div class="container zoomIn">

        <div class="calculadora">            
            <h4 id="sub"></h4>
            <input class="textview" id="textbox" value="0">
            <table>
                <tr>
                    <td><input class="button" type="button" value="C" onclick="clean()"></td>
                    <td><input class="button" type="button" value="DEL" onclick="del()"></td>
                    <td><input class="button" type="button" value="÷" onclick="inserirFuncao('÷')"></td>
                    <td><input class="button" type="button" value="x" onclick="inserirFuncao('x')"></td>
                    <td><input class="button" type="button" value="(" onclick="inserirNumero('(')"></td>
                    <td><input class="button" type="button" value=")" onclick="inserirNumero(')')"></td>
                </tr>
                <tr>
                    <td><input class="button" id="numeros" type="button" value="7" onclick="inserirNumero(7)"></td>
                    <td><input class="button" id="numeros" type="button" value="8" onclick="inserirNumero(8)"></td>
                    <td><input class="button" id="numeros" type="button" value="9" onclick="inserirNumero(9)"></td>
                    <td><input class="button" type="button" value="-" onclick="inserirFuncao('-')"></td>
                    <td><input class="button" type="button" value="√" onclick="inserirFuncao('√')"></td>                    
                </tr>
                <tr>
                    <td><input class="button" id="numeros" type="button" value="4" onclick="inserirNumero(4)"></td>
                    <td><input class="button" id="numeros" type="button" value="5" onclick="inserirNumero(5)"></td>
                    <td><input class="button" id="numeros" type="button" value="6" onclick="inserirNumero(6)"></td>
                    <td><input class="button" type="button" value="+" onclick="inserirFuncao('+')"></td>
                    <td><input class="button" type="button" value="n!" onclick="inserirFuncao('!')"></td>
                   
                    
                </tr>
                <tr>
                    <td><input class="button" id="numeros" type="button" value="1" onclick="inserirNumero(1)"></td>
                    <td><input class="button" id="numeros" type="button" value="2" onclick="inserirNumero(2)"></td>
                    <td><input class="button" id="numeros" type="button" value="3" onclick="inserirNumero(3)"></td>
                    <td rowspan="5"><input class="button" id="igual" type="button" value="=" onclick="equals()"></td>
                   
              
                </tr>
                <tr>
                    <td><input class="button" id="zero" type="button" value="0" onclick="inserirNumero(0)"></td>
                    <td><input class="button" type="button" value="." onclick="inserirNumero('.')"></td>                   
                    <td><input class="button" type="button" value="x" onclick="inserirFuncao('x')"></td>
                </tr>

            </table>
        </div>
        <div class="hist">
            <h1>Histórico</h1>
            <table id="historico">

            </table>
            <input type="button" class="btnLimpar" value="Limpar" onclick="cleanHist()"> 
        </div>
       
    </div>

    <!-- JavaScript -->
    <script src="assets/js/calculator.js"></script>
    <script src="assets/js/jquery.min.js"></script>

</body>
</html>