A towel is 12 yuan, and the price of 5 handkerchiefs is 45 yuan, so how much is a handkerchief cheaper than a towel?
一条毛巾12元，5块手帕的价钱是45元，那么一块手帕比一条毛巾便宜多少钱？
<gadget id="calculator">45 / 5</gadget>
<output>9</output>

<gadget id="calculator">12 - 9</gadget>
<output>3</output>

<result>3</result>