[spronkey]

That's quite untrue for more complex examples of 7 + 17.

"Hey Dingbat, what's 10 percent of 50 times 33 times 125. Oh sorry, 10 percent of open parentheses 50 times 33 times 125 close parentheses".

Even just talking it is substantially slower than typing the number into a calculator. App, desktop, or phone.

[ribchinski]

Especially when there are parenthesis. And when you are in the kitchen, well... it is loud. Accents mess the voice recognition + the sound of the kitchen.