132 There is a group of children, all of whose ages are integers. One of them is 10 years old. If the oldest is 13 years old, the sum of the ages of all the children is 50 years, and except for the 10-year-old child, the ages of the other children form an arithmetic sequence in order of size, this group of children has $\qquad$ members.
132 5. Removing the 10-year-old child, the sum of the ages of the remaining children is 40, the oldest is 13 years old, $3 \times 13<40$, so there must be at least 4 children. The average age of the oldest and the youngest (at least 1 year old) is $\geqslant 6$, and this average is a divisor of 40, so it can only be 10 or 8, meaning the number of children is 4 or 5. It is easy to verify that $7, 9, 11, 13$ form an arithmetic sequence and their sum is 40. When the number of children is 5, there will be a non-integer age.
Therefore, the total number of children is $4+1=5$.