The supermarket originally had 35 windmills. After selling 28, another 30 were shipped. How many windmills are there in the supermarket?
超市原来有35个风车，卖出28个后，又运来30个，这时超市有风车多少个？
<gadget id="calculator">35 - 28</gadget>
<output>7</output>

<gadget id="calculator">7 + 30</gadget>
<output>37</output>

<result>37</result>