The little squirrel can pick 20 pine nuts per day on sunny days and 12 per day on rainy days. It picked 116 pine nuts in total last week. How many days were rainy last week?
小松鼠采松子，晴天每天可以采20个，雨天每天可以采12个，它上个星期共采了116个松子．上星期中有几天是雨天？
<gadget id="calculator">20 * 7</gadget>
<output>140</output>

<gadget id="calculator">140 - 116</gadget>
<output>24</output>

<gadget id="calculator">20 - 12</gadget>
<output>8</output>

<gadget id="calculator">24 / 8</gadget>
<output>3</output>

<result>3</result>