On the first day of school, Mrs. McGillicuddy had 25 students registered for the morning session of kindergarten, but 3 students were absent; and she had 24 students registered for the afternoon session, but 4 students were absent. How many students did Mrs. McGillicuddy have over the two kindergarten sessions?
25-3=<<25-3=22>>22 students
24-4=<<24-4=20>>20 students
She had 22+20=<<22+20=42>>42 students
#### 42