If a piece of wood is sawed into 4 sections, the sawing fee will be 2.4 yuan. If it is sawn into 12 sections, how much will it cost?
一根木头，锯成4段要付锯板费2.4元，如果锯成12段，要付多少元．
<gadget id="calculator">4 - 1</gadget>
<output>3</output>

<gadget id="calculator">2.4 / 3</gadget>
<output>0.8</output>

<gadget id="calculator">12 - 1</gadget>
<output>11</output>

<gadget id="calculator">0.8 * 11</gadget>
<output>8.8</output>

<result>8.8</result>