Math-bait

When a Maths question tries to trick you/when you think you finished your maths work but there is more to do

*John* Ok let's do this maths question. *sees the question and gets confused* huh whats this ahh its trying to math-bait me.
*Student* Finally I'm done! Miss I'm finished! *Teacher comes and checks his work* sees that he has one left* *Teacher* Actually you have not. *Shows him the extra sheet* *Student screams*