John ends up damaging his hearing aids.  He needs to replace both of them.  They cost $2500 each.  Insurance covers 80% of the cost.  How much does he personally have to pay?
The cost of the hearing aids is $2500 * 2 = $
<gadget id="calculator">2500*2</gadget>
<output>5_000</output>
5000.
So insurance covers $5000 * .8 = $
<gadget id="calculator">5000*.8</gadget>
<output>4_000</output>
4000.
That means it cost him $5000 - $4000 = $
<gadget id="calculator">5000-4000</gadget>
<output>1_000</output>
1000.

<result>1_000</result>