These have been specifically assigned to your child during band class, but by all means, let them play ahead if they want and are able! My favorite part of the day is when a child shows me something new they learned all by themselves! :)
At a minimum, your child should be practicing what's listed, but please encourage them to take the initiative to do even more. All students should be playing at home 4-5 days a week, 15-20 minutes each practice/homework session.
W= Warm-Up exercise for the next lesson
R= Exercise (s) that need to be reviewed for the next lesson
HW= New exercises to work on for the next lesson
T= Exercise you will be tested on
EC= Extra Credit