Final answer:
Each classroom will get 3 balls, with 1 ball left over.
Step-by-step explanation:
To find out how many balls each classroom will get, we can divide the total number of balls by the number of classrooms. In this case, we have 13 balls and 4 classrooms. So, we divide 13 by 4:
13 ÷ 4 = 3 remainder 1
Each classroom will get 3 balls, with 1 ball left over.