The physical education teacher bought 3 small basketballs, paid 70 yuan, and got 7 yuan back. How much is each small basketball?
体育教师买了3个小篮球，付出70元，找回7元，每个小篮球多少元？
<gadget id="calculator">70 - 7</gadget>
<output>63</output>

<gadget id="calculator">63 / 3</gadget>
<output>21</output>

<result>21</result>