Lizzy: 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?.
Me: Hmmm, let me think. I think this is the detailed solution:
25 - 3 = 22 students. 24 - 4 = 20 students. She had 22 + 20 = 42 students. Final answer: 42.