In a certain place in September, sunny days account for (2/3), cloudy days account for 3 days, and the rest are rainy days. How many days are there rainy days?
某地九月份晴天占(2/3)，阴天有3天，其余是雨天，雨天有几天？
<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">30 * (2/3)</gadget>
<output>20</output>

<gadget id="calculator">30 - 20 - 3</gadget>
<output>7</output>

<result>7</result>