Add 7 to a number, multiply by 5, and then subtract 9 to get 66. What is this number?
一个数加7，乘5，再减去9，得66，这个数是多少．
<gadget id="calculator">66 + 9</gadget>
<output>75</output>

<gadget id="calculator">75 / 5</gadget>
<output>15</output>

<gadget id="calculator">15 - 7</gadget>
<output>8</output>

<result>8</result>