How do I sum all the values based on each day. This is data for number of
computers being used in a lab. I would like to know the total number of
computers used for each day the entire semester. Thanks.

Day 7:30 AM 8:30 9:30
Mon 1 2 8
Tue 1 0 2
Wed 0 2 4
Thu 1 3 9
Mon 4 5 12
Tue 2 1 16
Wed 2 2 4
Thu 1 3 5