Or if somehow youre too lazy to:
$${\mathtt{18\,349}}{\mathtt{\,-\,}}{\mathtt{6\,543}}{\mathtt{\,\small\textbf+\,}}{\mathtt{12\,435}}{\mathtt{\,-\,}}{\mathtt{6}} = {\mathtt{24\,235}}$$
You can enter this into the onsite calculator.....it will give you the answer...
Or if somehow youre too lazy to:
$${\mathtt{18\,349}}{\mathtt{\,-\,}}{\mathtt{6\,543}}{\mathtt{\,\small\textbf+\,}}{\mathtt{12\,435}}{\mathtt{\,-\,}}{\mathtt{6}} = {\mathtt{24\,235}}$$