 class="chip" title="Division">
              <input type="checkbox" id="op-div" checked />
              <span>&divide;</span>
            </label>
          </div>
        </div>
        <div class="group small">
          <label for="duration">Timer</label>
          <select id="duration" aria-label="Duration">
            <option value="30">30 seconds</option>
            <option value="60" selected>60 seconds</option>
            <option value="120">2 minutes</option>
            <option value="180">3 