The school cafeteria brings (4/5) tons of rice, eats (1/7) every day, how many days can it be eaten.
学校食堂运来(4/5)吨大米，每天吃去(1/7)，多少天可吃完．
<gadget id="calculator">1 / 7</gadget>
<output>1/7 = around 0.142857</output>

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

<result>7</result>