Mingming plans to practice 260 brush characters, but has already practiced 180 characters, and the rest will take 5 days to complete. Obviously, how many characters should be practiced on average every day.
明明计划练260个毛笔字，已经练了180个字，剩下的要5天完成，明明平均每天要练多少个字．
<gadget id="calculator">260 - 180</gadget>
<output>80</output>

<gadget id="calculator">80 / 5</gadget>
<output>16</output>

<result>16</result>