I strongly remember these precise type of pink erasers from elementary school.  Instead of listening to my class assignments, I'd try to stick the corner of these erasers up my nostrils!  Luckily I only managed to push them up there part way- not enough to cause sinus issues or anything, hehe.  The outcome of my little shenanigans is that these erasers smell much stronger to me than they would for the average person who uses them.  Other times I'd chew on them like a dog and spit eraser particles all over the room.  You see, I had a hard time paying attention to my daily assignments so I had to find ways to entertain myself... and eraser munching just shows how bored I really was sitting in the same darn seat every darn day.  Those were the days.  Anyway these erasers are guaranteed to last you a really long time.  I mean REALLY long time- as long as you don't give in to biting or sniffing them, just one eraser should last a whole year.  With 3 erasers... do the math (since I can't).  3 erasers equals a really long time.