The school bought 28 basketballs, one more than three times the number of footballs. How many footballs did the school buy? (solution by equation)
学校买来28个篮球，比足球的3倍还多1个，学校买来足球多少个？(用方程解)
<gadget id="calculator">28 - 1</gadget>
<output>27</output>

<gadget id="calculator">27 / 3</gadget>
<output>9</output>

<result>9</result>