калькулятор

<div class="calculator">
        <input type="text" id="result" disabled>
        <div class="buttons">
            <button onclick="clearResult()">C</button>
            <button onclick="appendToResult('7')">7</button>
            <button onclick="appendToResult('8')">8</button>
            <button onclick="appendToResult('9')">9</button>
            <button onclick="appendToResult('/')">/</button>

<button onclick="appendToResult('4')">4</button>
            <button onclick="appendToResult('5')">5</button>
            <button onclick="appendToResult('6')">6</button>
            <button onclick="appendToResult('*')">*</button>

<button onclick="appendToResult('1')">1</button>
            <button onclick="appendToResult('2')">2</button>
            <button onclick="appendToResult('3')">3</button>
            <button onclick="appendToResult('-')">-</button>

<button onclick="appendToResult('0')">0</button>
            <button onclick="calculateResult()">=</button>
            <button onclick="appendToResult('+')">+</button>
        </div>
    </div>

<script src="script.js"></script>

Results: