If the school cafeteria uses a pile of coal for 3 days (3/7), how much of this pile of coal is used on average every day.
学校食堂3天用一堆煤的(3/7)，则平均每天用去这堆煤的多少．
<gadget id="calculator">3 / 7</gadget>
<output>3/7 = around 0.428571</output>

<gadget id="calculator">(3/7) / 3</gadget>
<output>1/7 = around 0.142857</output>

<result>1/7 = around 0.142857</result>