Divide a number by 5, add 8.5, the result is 10, what is the number
一个数除以5，再加上8.5，结果是10，这个数是多少
<gadget id="calculator">10 - 8.5</gadget>
<output>1.5</output>

<gadget id="calculator">1.5 * 5</gadget>
<output>7.5</output>

<result>7.5</result>