Siri Mathematical Calculations

When I ask Sire to multiply 32 x 44, it speaks the reply. When I ask Siri to multiply $200,000 by 18, it says “I found the answer, it’s displayed on your iPhone.” Not sure when or why the numbers switch from being spoken to being displayed, but I can’t stop the car in time to see the result displayed on the phone screen. Don’t do it a lot, but when I’m talking and driving, I have to get my passenger to use their phone to do the more complex calculations.