Lele wanted to donate the coins in the piggy bank to the disaster area. He calculated and found that there were only 1 yuan and 5 cents coins. There were 18 coins in total, totaling 14 yuan.
乐乐想把储蓄罐里的硬币捐给灾区，他算了算，发现只有1元和5角两种硬币，一共有18枚，合计14元，其中5角的硬币有多少枚．
<gadget id="calculator">0.5 * 18</gadget>
<output>9</output>

<gadget id="calculator">14 - 9</gadget>
<output>5</output>

<gadget id="calculator">1 - 0.5</gadget>
<output>0.5</output>

<gadget id="calculator">5 / 0.5</gadget>
<output>10</output>

<gadget id="calculator">18 - 10</gadget>
<output>8</output>

<result>8</result>