The little squirrel can pick 10 pine cones a day on sunny days, but only 6 pine cones on rainy days. It picked 80 pine cones for several days, with an average of 8 per day. So how many days are rainy days?
小松鼠采松果，晴天每天可以采10个，雨天每天只能采6个．它一连几天采了80个松果，平均每天采8个．那么其中有几天是雨天呢？
<gadget id="calculator">80 / 8</gadget>
<output>10</output>

<gadget id="calculator">10 * 10</gadget>
<output>100</output>

<gadget id="calculator">100 - 80</gadget>
<output>20</output>

<gadget id="calculator">10 - 6</gadget>
<output>4</output>

<gadget id="calculator">20 / 4</gadget>
<output>5</output>

<result>5</result>