(7/10): 40=12: how much.
(7/10)：40=12：多少．
<gadget id="calculator">7 / 10</gadget>
<output>7/10 = around 0.7</output>

<gadget id="calculator">12 / (7/10)</gadget>
<output>120/7 = around 17.142857</output>

<gadget id="calculator">40 * (120/7)</gadget>
<output>4_800/7 = around 685.714286</output>

<result>4_800/7 = around 685.714286</result>