There are 15 children playing hide and seek together, 5 of them have been caught, and how many are left.
有15个小朋友一起玩捉迷藏游戏，已捉到5个、还剩多少个没捉到．
<gadget id="calculator">15 - 1 - 5</gadget>
<output>9</output>

<result>9</result>