Prepare a certain medicine, the ratio of medicine to water is 1:6, how many grams of medicine are contained in 140 grams of this medicine.
配制某种药水，药与水的比为1：6，140克这种药水中含药多少克．
<gadget id="calculator">1 + 6</gadget>
<output>7</output>

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

<gadget id="calculator">140 * (1/7)</gadget>
<output>20</output>

<result>20</result>