2.4: (3/7).
2.4：(3/7)．
<gadget id="calculator">12 / 5</gadget>
<output>12/5 = around 2.4</output>

<gadget id="calculator">3 / 7</gadget>
<output>3/7 = around 0.428571</output>

<gadget id="calculator">(12/5) / (3/7)</gadget>
<output>28/5 = around 5.6</output>

<result>28/5 = around 5.6</result>