Naughty bought 3 footballs, gave the salesperson 300 yuan, got back 30 yuan, how much is each football?
淘气买了3个足球，给售货员300元，找回了30元，每个足球多少元？
<gadget id="calculator">300 - 30</gadget>
<output>270</output>

<gadget id="calculator">270 / 3</gadget>
<output>90</output>

<result>90</result>