Little Tommy (who was Jewish) was doing very badly  in math.  His parents had tried tutors.  They tried everything they could think of.  Finally, in a last ditch effort, they took Tommy down and enrolled him in the local Catholic school.  After the first day, little Tommy came home with a very serious look on his face.  He didn't even kiss his mother hello. Instead, he went to his room and started studying.  Books and papers were spread out all over the room and little Tommy was hard at work.  His mother was amazed.  She called him down to dinner and, to her shock, the minute he was done, he marched back to his room without a word and, in no time, was back hitting the books as before.

This went on for some time, day after day, while the mother tried to
understand what made all the difference.   Finally, little Tommy brought
home his report card.  He quietly laid it on the table and went to his room
and hit the books.  With great trepidation, his mom looked at it and, to her
surprise, little Tommy got an "A" in math!

She could no longer hold her curiosity.  She went to his room and said,
"Son, what was it?  Was it the nuns?"  Little Tommy looked at her and shook
his head no.

"Well then," she asked, "was it the books, the discipline, the structure,
the uniforms?  What was it?"

Little Tommy looked at her and said, "Well, on the first day of school, when
I saw that guy nailed to the plus sign, I knew they weren't fooling around."