A number is enlarged by 13 times, which is 72 more than the original number. What is the original number?
一个数扩大13倍，比原来的数增加了72，原来这个数是多少．
<gadget id="calculator">13 - 1</gadget>
<output>12</output>

<gadget id="calculator">72 / 12</gadget>
<output>6</output>

<result>6</result>