SSRS 2008 - How to Total values from an expression

I'm trying to figure out how to total values from a calculated field. In the example below, I have the following expression: =IIF(Fields!Role.Value = "Contractor", Fields!actualwork.Value * 100, Fields!actualwork.Value * 77) Now I want to provide a total, but it doesn't show up on the report. Is there something I'm missing? " class="img-fluid rounded" style="max-width: 100%; height: auto; margin: 10px 0;" loading="lazy">