A piece of iron wire is 12m long, and (4/5) is used up. How much less is the remaining meter than the used one?
一根铁丝长12m，用去了(4/5)，剩下的比用去的少多少米？
<gadget id="calculator">4 / 5</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">12 * (4/5)</gadget>
<output>48/5 = around 9.6</output>

<gadget id="calculator">12 - (48/5)</gadget>
<output>12/5 = around 2.4</output>

<gadget id="calculator">(48/5) - (12/5)</gadget>
<output>36/5 = around 7.2</output>

<result>36/5 = around 7.2</result>