In a ratio, the product of two outer terms is the smallest prime number, one inner term is 0.5, and the other inner term is what.
在一个比例里，两个外项的积是最小的质数，一个内项是0.5，另一个内项是多少．
<gadget id="calculator">2 / 0.5</gadget>
<output>4</output>

<result>4</result>