Mark has a really bad headache.  He takes 2 Tylenol tablets of 500 mg each and he does every 4 hours for 12 hours.  How many grams of Tylenol does he end up taking?
He takes 12/4=
<gadget id="calculator">12/4</gadget>
<output>3</output>
3 doses.
Each dose is 500*2=
<gadget id="calculator">500*2</gadget>
<output>1_000</output>
1000 mg.
So he takes 3*1000=
<gadget id="calculator">3*1000</gadget>
<output>3_000</output>
3000 mg.
So he takes 3000/1000=
<gadget id="calculator">3000/1000</gadget>
<output>3</output>
3 grams of Tylenol.

<result>3</result>