CODE EXAMPLE FOR JAVASCRIPT

calculator

<div class="calculator__keys">
  <button class="key--operator" data-action="add">+</button>
  <button class="key--operator" data-action="subtract">-</button
  <button class="key--operator" data-action="multiply">&times;</button>
  <button class="key--operator" data-action="divide">÷</button
  <button>7</button>
  <button>8</button>
  <button>9</button>
  <button>4</button>
  <button>5</button>
  <button>6</button>
  <button>1</button>
  <button>2</button>
  <button>3</button>
  <button>0</button>
  <button data-action="decimal">.</button>
  <button data-action="clear">AC</button>
  <button class="key--equal" data-action="calculate">=</button>
</div>