Kris is trying to earn a video game achievement for playing a total of 30 hours. If Kris plays for half an hour every day for 2 weeks then plays for 2 hours every day for a week, how many hours does she still need to play to earn the achievement?
Two weeks is the same as 2 weeks * 7 days = 
<gadget id="calculator">2*7</gadget>
<output>14</output>
14 days.
So playing for half an hour every day means Kris will have played for 0.5 hours * 14 days = 
<gadget id="calculator">0.5*14</gadget>
<output>7</output>
7 hours.
Playing for 2 hours every day for another week will be an additional 2 hours * 7 days = 
<gadget id="calculator">2*7</gadget>
<output>14</output>
14 hours.
She therefore still needs to play 30 - 7 - 14 = 
<gadget id="calculator">30-7-14</gadget>
<output>9</output>
9 hours.

<result>9</result>