Can I use Wolfram Alpha to make a widget for this? That seems to work. Also, in this version I included the units in the input box. Why not – right? Wolfram Alpha interprets that stuff anyway.

Today, we're looking at Siri's Wolfram Alpha integration. You can force Siri to use Wolfram by prefixing your request with "Wolfram." For example, you might say, "Wolfram, what is the square root ...

Type how you're related into Wolfram Alpha's computation engine, and it returns the relationship—first cousin once removed, in that last example.