Ineed and fast (5th grader) on numbers 4, 5, 6

4. 22 rows - 19 rows = 3 rows, 3 rows/2 = 1.5 rows, 1.5 rows x 4 seats =
   6 seats remaining.
5. 13 1/2 years + 11 1/2 years = 25 years, 89 yeas - 25 years =
   64 years older
6. 29 adults + 22 children = 51 people, 51/4 = 12 full rafts with the
   last raft seating 3 people. 

The answer to 4 is 6 seats left or 1 1/2 rows left because 22-19=3 and 3/2=1 1/2