A candle melts by 2 centimeters every hour that it burns. How many centimeters shorter will a candle be after burning from 1:00 PM to 5:00 PM?
The candle burns for 5 - 1 = 
<gadget id="calculator">5-1</gadget>
<output>4</output>
4 hours.
Thus, the candle will be 2 * 4 = 
<gadget id="calculator">2*4</gadget>
<output>8</output>
8 centimeters shorter.

<result>8</result>