The marching band organizes 80 students into 6 lines. how many students are in each line and how many students are left over?

Do do this, we can simply divide 80 by 6.
First, lets find how many times 6 can go into 80.
6 goes into 80 13 times without going over.
Now, we multiply 13x6 and that's 78.
Since there was 80 to begin with, and we ended up with 78, there would be 2 people left over. So:
There are 13 students in each line and 2 left over.