Students in class 31 folded 999 thousand paper cranes for the teacher. It has been 7 days, with an average of 109 per day, how many more?
三1班同学给老师折999只千纸鹤，已经折了7天，平均每天折109只，还要折多少只？
<gadget id="calculator">109 * 7</gadget>
<output>763</output>

<gadget id="calculator">999 - 763</gadget>
<output>236</output>

<result>236</result>