PDF Calculation - Sum of related attributes

[boognish]

I would like to know how to handle "sum" calculations inside PDF templates.

For example - the below lists out "name" and sundryPrice" for a record with one-to-many "sundries" relationship:

{{#each sundries}}
    {{name}} - R{{sundryPrice}}<br>
{{/each}}

All I have left is to add the prices together, but not sure about the syntax from within the PDF template editor. Any help would be greatly appreciated!