Jeff was driving to the capital city to attend a conference. At first, he was driving at 80 miles/hour for about 6 hours, then the speed limit changed and he had to slow down to 60 miles/hour, and so he drove at this speed for 4 hours. Then he made a stop at a gas station. Once the car was full of gas, he drove at 40 miles/hour the rest of the trip for 2 hours. How many miles did he travel?
In the first stretch he drove 80 miles/hour x 6 hours = 
<gadget id="calculator">80*6</gadget>
<output>480</output>
480 miles.
In the second stretch he drove 60 miles/hour x 4 hours = 
<gadget id="calculator">60*4</gadget>
<output>240</output>
240 miles.
After the gas station he drove 40 miles/hour x 2 hours = 
<gadget id="calculator">40*2</gadget>
<output>80</output>
80 miles.
In total he drove 480 miles + 240 miles + 80 miles = 
<gadget id="calculator">480+240+80</gadget>
<output>800</output>
800 miles.

<result>800</result>