James paves a new parking lot.  It is 400 feet by 500 feet.  Only 80% of that is useable for parking.  It takes 10 square feet to park a car.  How many cars can be parked?
The parking lot is 400*500=
<gadget id="calculator">400*500</gadget>
<output>200_000</output>
200,000.
There are 200,000*.8=
<gadget id="calculator">200000*.8</gadget>
<output>160_000</output>
160,000 square feet of parking space.
That means he can park 16,0000/10=16000 cars.

<result>16_000</result>