Subtract 8 from a number, add 4, and multiply by 5. The result is 25. What is the number?
一个数减去8，加上4，再乘5的结果是25，这个数是多少．
<gadget id="calculator">25 / 5</gadget>
<output>5</output>

<gadget id="calculator">5 - 4</gadget>
<output>1</output>

<gadget id="calculator">1 + 8</gadget>
<output>9</output>

<result>9</result>