The third-grade students do handicrafts, and they have to make 100 in a week. They have already made 40 in the first three days, and the rest have to be done in 4 days. How many do they make on average in the remaining four days?
三年级同学做手工，一周内要做100个，前三天已经做了40个，余下的要在4天内做完，剩下四天平均每天要做多少个？
<gadget id="calculator">100 - 40</gadget>
<output>60</output>

<gadget id="calculator">60 / 4</gadget>
<output>15</output>

<result>15</result>