There are 40 calves on the farm, which is 5/7 of the big cows. How many big cows are there on the farm?
农场有小牛40头，是大牛头数的(5/7)，农场有大牛多少头？
<gadget id="calculator">5 / 7</gadget>
<output>5/7 = around 0.714286</output>

<gadget id="calculator">40 / (5/7)</gadget>
<output>56</output>

<result>56</result>