How to do arithmetic operations in Laravel blade view?

I want to do subtraction operation inside Laravel blade view. I knew it was the wrong approach I need to do it from controller,but can someone give me the proper solution to do it directly inside blade view?

Note : I am a newbie to programming.

Here is my code

@if(!empty($receipt_details->total_due))
                 <tr>
                    <th>
                        Customer Old Due 
                    </th>
                    <td>
                         - 
                    </td>
                </tr>
 @endif

via Chebli Mohamed