John has a donkey and an elephant.  The elephant weighs 3 tons (a ton is 2000 pounds).  The donkey weighs 90% less.  What is their combined weight in pounds?
The elephant weighs 3*2000=
<gadget id="calculator">3*2000</gadget>
<output>6_000</output>
6000 pounds.
The donkey weighs 6000*.9=
<gadget id="calculator">6000*.9</gadget>
<output>5_400</output>
5400 pounds less.
So the donkey weighs 6000-5400=
<gadget id="calculator">6000-5400</gadget>
<output>600</output>
600 pounds.
That means the combined weight is 600+6000=
<gadget id="calculator">600+6000</gadget>
<output>6_600</output>
6600 pounds.

<result>6_600</result>