ClientTemplate - Math Round \ String Format with no decimals

Hi,
I can get any data with the client template and it works fine, but i cannot find a way to round a 'Double' value as math round or in string.Format("C0")
in the client template. I want to round the dataItem.QuoteSumDollars which is a 'Double' with no decimal digits.
Here is my HtmlChart Series:

                           <Series>
                            <telerik:LineSeries Name="Quote" DataFieldY="QuoteSumDollars">
                                <LabelsAppearance>
                                    <ClientTemplate>
                                         #=dataItem.QuoteSumDollars#
                                    </ClientTemplate>
                                </LabelsAppearance>
                                <TooltipsAppearance>
                                    <ClientTemplate>
                                        Quote #=dataItem.QuoteID#
                                    </ClientTemplate>
                                </TooltipsAppearance>
                            </telerik:LineSeries>
                        </Series>

Many thanks.