Choose two prime numbers arbitrarily within 20, and you can write a fraction, which is the smallest.
在20以内任意选两个质数，就可以写一个分数，其中最小的是多少．
<gadget id="calculator">2 / 19</gadget>
<output>2/19 = around 0.105263</output>

<result>2/19 = around 0.105263</result>