whats the answer

Just use the calculator on the home page here and type it in exactly as you've written it.

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wow 10 points.

$${\mathtt{1\,340.96}}{\mathtt{\,\small\textbf+\,}}{\mathtt{3\,236.8}}{\mathtt{\,\small\textbf+\,}}{\mathtt{693.6}} = {\mathtt{5\,271.36}}$$