I need to multiply HTML values which contains two numbers like the following:

```html
<span class="elementClass">firstNumber / secondNumber</span>
<!-- for example -->
<span class="elementClass">2000 / 4000</span>

```

How do I get each number separately and multiply it for example by 2 and get value '4000 / 8000'.

Maybe something like this:

```
let m = $('.elementClass')[0].innerHTML;
$('.elementClass')[0].innerHTML = m * 2;

```