18. Master Li made 8 identical rabbit lanterns in 3 days, making at least 1 lantern each day. Master Li has ( ) different ways to do this.
【Answer】 21 ways.
【Analysis】Exam point: Enumeration method and addition-multiplication principle
Make 1 lantern each day, and there are still $8-3=5$ lanterns to be made.
(1) If these 5 lanterns are completed in 1 day, there are 3 ways;
(2) If these 5 lanterns are completed in 2 days, $5=1+4$ or $5=2+3$;
If 1 lantern is made one day and 4 lanterns the next day, there are $3 \times 2=6$ (ways) to do it;
If 2 lanterns are made one day and 3 lanterns the next day, there are $3 \times 2=6$ (ways) to do it;
(3) If these 5 lanterns are completed in 3 days, $5=1+1+3$ or $5=1+2+2$;
If 3 lanterns are made one day and 1 lantern each on the other two days, there are 3 ways;
If 1 lantern is made one day and 2 lanterns each on the other two days, there are 3 ways; so in total, there are $3+6+6+3+3=21$ (ways) to do it.