Xiao Ming did 105 cross-point math problems, and Xiao Min did 18 problems per minute on average for 5 minutes. Who did more? How much more?
小明做了105道口算题，小敏平均每分钟做18道，做了5分钟，谁做的多？多多少道？
<gadget id="calculator">18 * 5</gadget>
<output>90</output>

<gadget id="calculator">105 - 90</gadget>
<output>15</output>

<result>15</result>