John books 3 nights at a hotel room for $250 a night.  He has a $100 discount.  How much does he pay?
The cost is 250*3=$
<gadget id="calculator">250*3</gadget>
<output>750</output>
750.
So he spends 750-100=$
<gadget id="calculator">750-100</gadget>
<output>650</output>
650.

<result>650</result>