any way to do math with values? I can put them up like this:

<BigValue data = {single_total_matches} 
    value = 'single_total_matches'
/>
<BigValue data = {multi_total_matches} 
    value = 'multi_total_matches'
/>

and then I'd like to add those two together, but using

{}

throws an error

Probably the easiest way would be to write a third query which adds the two and reference that in another BigValue!

yeah, they're looking at different tables and I was hoping to be a bit lazier

You can reference any queries you already have like this https://docs.evidence.dev/features/queries/query-chaining