Teacher Li and Teacher Zhang bought the same small football. Teacher Li bought 5 and Teacher Zhang bought 8. Teacher Li paid 90 yuan less than Teacher Zhang. How much is each small football?
李老师和张老师买同样的小足球，李老师买了5个，张老师买了8个，李老师比张老师少付90元，每个小足球多少元？
<gadget id="calculator">8 - 5</gadget>
<output>3</output>

<gadget id="calculator">90 / 3</gadget>
<output>30</output>

<result>30</result>