Teacher Li spent 450 yuan to buy 18 small footballs. The school wants to buy 15 more such small footballs. How much money does it need to prepare?
李老师买18个小足球用了450元，学校还想再买15个这样的小足球，需准备多少钱？
<gadget id="calculator">450 / 18</gadget>
<output>25</output>

<gadget id="calculator">25 * 15</gadget>
<output>375</output>

<result>375</result>