Mr. Wang bought 15 footballs with 900 yuan, and there is 30 yuan left. How much is each football?
王老师带900元钱，买了15个足球，还剩下30元，每个足球多少元？
<gadget id="calculator">900 - 30</gadget>
<output>870</output>

<gadget id="calculator">870 / 15</gadget>
<output>58</output>

<result>58</result>