frog eats 70 pests every day, 10 less than twice as much as a magpie. How many pests does this magpie eat every day?
一只青蛙每天吃70只害虫，比一只喜鹊吃的2倍少10只．这只喜鹊每天吃害虫多少只？
<gadget id="calculator">70 + 10</gadget>
<output>80</output>

<gadget id="calculator">80 / 2</gadget>
<output>40</output>

<result>40</result>