Answer:
Auggie's dad made fun of the principal's name to try to convince him to go to school.
(Edit: assuming the book is 'Wonder' by R.J. Palacio.)
Explanation:
In page 13, we read a passage of a dialogue between Auggie and his dad where dad points out the first part of the principal's name, Tushman. Being a ridiculous name, Auggie's dad says that he "should go to that school just so you can hear his name said over the loudspeaker".
