Teacher Li went to the stationery store and bought 9 small footballs, and paid the salesperson 100 yuan, and I returned 28 yuan. How much is each small football?
李老师到文具店买了9个小足球，付给营业员100元，我回了28元，每个小足球多少元？
<gadget id="calculator">100 - 28</gadget>
<output>72</output>

<gadget id="calculator">72 / 9</gadget>
<output>8</output>

<result>8</result>