Xiao Ming typed a 3,500-word manuscript, and he typed 990 Chinese characters in 11 minutes. According to this calculation, how many Chinese characters are still left to be typed in half an hour?
小明打一份3500字的稿件，他11分钟打了990个汉字，照这样计算，半小时后还有多少个汉字没有打完？
<gadget id="calculator">990 / 11</gadget>
<output>90</output>

<gadget id="calculator">90 * 30</gadget>
<output>2_700</output>

<gadget id="calculator">3_500 - 2_700</gadget>
<output>800</output>

<result>800</result>