The number A is the reciprocal of the number B. After the number B is enlarged by 10 times, it is 30. What is the number A?
甲数是乙数的倒数，乙数扩大10倍后是30，甲数是多少．
<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<result>1/3 = around 0.333333</result>