Master Wang used to be able to process 720 parts in 6 hours, but now he can process 150 parts per hour. How many more parts are processed per hour now than before?
王师傅原来6小时能加工720个零件，现在每小时能加工150个零件．现在比原来每小时多加工多少个零件？
<gadget id="calculator">720 / 6</gadget>
<output>120</output>

<gadget id="calculator">150 - 120</gadget>
<output>30</output>

<result>30</result>