John is raising money for a school trip. He has applied for help from the school, which has decided to cover half the cost of the trip. How much money is John missing if he has $50 and the trip costs $300?
John's school has decided to pay 300 / 2 = $
<gadget id="calculator">300/2</gadget>
<output>150</output>
150 for his trip.
In total John has covered 150 + 50 = $
<gadget id="calculator">150+50</gadget>
<output>200</output>
200 for his trip.
Therefore, John needs 300 - 200 = $
<gadget id="calculator">300-200</gadget>
<output>100</output>
100 more for the trip.

<result>100</result>