A trick I've started to use with davinci is prompting it to use a calculator for all math

I preprompt it to believe it's math cannot be trusted (because it can't) and to instead output "!c <insert basic calculations>" any time it would otherwise try to solve something

The next step I'm working on this weekend is piping that to Wolfram Alpha and seeing if I can put together a wrapper to make it "seamless" in terms of responses