Sieve = Thief

In Geometry, I wrote "The Sieve of Eratosthanes" and the class erupted in laughter. I asked them what was so funny and one boy in the back row shouted out, "You could write 'thief' instead of 'sieve' and Chan* would say the exact same thing!" 

Obviously I needed to test out this theory, and I know that Chan is a good sport, so I turned to him and asked him to read what was on the board.

"Da seef of Ersafonies."

Then I changed sieve to thief and asked him to read it. No joke, EXACTLY THE SAME. 

I gave him some candy for his troubles.

*Names have been changed to protect the sheepish.